I've been DMing the HPE series of 4E adventures since 4E came out, mostly on a fortnightly basis. At this point, the characters are around 24th level and we're playing through E2-Kingdom of the Ghouls.
I thought that a brief capsule summary of what I think of each adventure might prove interesting:
H1 Keep on the Shadowfell
Absolutely awesome start to the series, with good NPCs to interact with in town (with suggestions to how they develop), plus the rising threat from the kobolds which then lead into the Keep.
Unfortunately, it falls apart once the Keep is reached: the Keep is too linear and too long, and there isn't enough seeding of the Big Bad, so that you get to him and think "why is he performing a ritual?" It isn't "we must reach him in time", but rather "Who's that guy?" There are good encounters in the Keep, but the structure of the adventure falls apart at that points. First half of the adventure is 9/10, second half is 5/10, for a final score of 7/10.
H2 Thunderspire Labyrinth
Looks great, and solves a lot of pacing problems by splitting the adventure up into four or five mini-adventures: I appreciate that. Unfortunately, the main home base didn't get used enough in play by the PCs, causing them to be disassociated with the people they're trying to help, and the maths problems with the soldier duergar (which were also resistant to the wizard's main fire attack) made too many of the combats grindy. It'd play better now the wizard has more options.
The big bad isn't quite built up to enough, IMO. Final score of 6/10.
H3 Pyramid of Shadows
A really interesting setting and a lot of good backstory for Nerath is unfortunately devalued by the sheer boringness of the inhabitants. Every group is evil and every group attacks (or deceives you, then attacks). Eventually I rewrote the bandits to be more neutral and thus sympathetic allies of the PCs and had some respite from the constant combat. The upper levels looked interesting, but weren't. Really needs to be more dynamic than its mapped out to be, because it's hard to change as written. The other big problem is that you're no longer caring about the communities of the Nerath Vale at all, as you were in H1. This came back to hurt us in the next module. Score 3/10.
P1 King of the Trollhaunt Warrens
Our first taste of the Feywild, King of the Trollhaunt Warrens has a suitably involving and epic plot, with a lot of Celtic overtones. I had to sit down with my players and recast them as less mercenary-types, because the adventure wants heroes (as do later ones), and they'd lost that over H2 and H3. There wasn't quite enough in town to really invest the PCs with the import of their actions, and the warrens might be just a little long, but the final act is the right length and very, very evocative. 8/10.
P2 Demon Queen's Enclave
The highlight of the series, with great potential for roleplaying which became a lot of actual roleplaying. My group befriended the drow necromancer and the soldiers and wreaked havoc against the priestesses of Lolth, after first visiting them to see if they were worth befriending - they weren't, they liked the necromancer more.
The adventure also brings Orcus's plans back into the mix, and thus sets up the epic series. My main problem with the module comes from an overly linear final act, which also is just a bit too long. 9/10
P3 Assault on Nightwyrm Fortress
A disaster. It starts off well enough, going through the Tomb of Sartine, but then going through the walls of the fortress to reach the tower (or, rather, to find the keys to get into the tower) is forced, linear and dreadfully boring. There are some good encounters in there, but they're buried under the tedious length of it all. This adventure, more than any other one in the series, seems to have been hit by policy decisions that it should be possible to go through all the adventures as pure combat romps, and although P2 allowed roleplaying alternatives, they didn't survive into P3. Score 2/10.
E1 Death's Reach
The basic premise of E1 (souls being diverted to evil ends) is just too similar to P3, but the execution makes this one of the best adventures in the series. It's suitably epic: the group fight major forces aligned with Orcus, get to meet the Raven Queen (which was great, because as opposed to their normal brash manner, the group was completely speechless in her presence), and then go to a ancient battleground of the Dawn War. This one is setting up the entire Epic series of adventures, and it's a great start. The final act - the Reliquary of Timesus - is once again a little too long, but only a little. 8/10.
E2 Kingdom of the Ghouls
We've played one session of this one. Alas, it starts in Sigil! Argh! The link between E1 and E2 doesn't quite work, but I was able to salvage something. We'll see how this one goes. My PCs are very glad they have a cleric with them!
Cheers!
I thought that a brief capsule summary of what I think of each adventure might prove interesting:
H1 Keep on the Shadowfell
Absolutely awesome start to the series, with good NPCs to interact with in town (with suggestions to how they develop), plus the rising threat from the kobolds which then lead into the Keep.
Unfortunately, it falls apart once the Keep is reached: the Keep is too linear and too long, and there isn't enough seeding of the Big Bad, so that you get to him and think "why is he performing a ritual?" It isn't "we must reach him in time", but rather "Who's that guy?" There are good encounters in the Keep, but the structure of the adventure falls apart at that points. First half of the adventure is 9/10, second half is 5/10, for a final score of 7/10.
H2 Thunderspire Labyrinth
Looks great, and solves a lot of pacing problems by splitting the adventure up into four or five mini-adventures: I appreciate that. Unfortunately, the main home base didn't get used enough in play by the PCs, causing them to be disassociated with the people they're trying to help, and the maths problems with the soldier duergar (which were also resistant to the wizard's main fire attack) made too many of the combats grindy. It'd play better now the wizard has more options.
The big bad isn't quite built up to enough, IMO. Final score of 6/10.
H3 Pyramid of Shadows
A really interesting setting and a lot of good backstory for Nerath is unfortunately devalued by the sheer boringness of the inhabitants. Every group is evil and every group attacks (or deceives you, then attacks). Eventually I rewrote the bandits to be more neutral and thus sympathetic allies of the PCs and had some respite from the constant combat. The upper levels looked interesting, but weren't. Really needs to be more dynamic than its mapped out to be, because it's hard to change as written. The other big problem is that you're no longer caring about the communities of the Nerath Vale at all, as you were in H1. This came back to hurt us in the next module. Score 3/10.
P1 King of the Trollhaunt Warrens
Our first taste of the Feywild, King of the Trollhaunt Warrens has a suitably involving and epic plot, with a lot of Celtic overtones. I had to sit down with my players and recast them as less mercenary-types, because the adventure wants heroes (as do later ones), and they'd lost that over H2 and H3. There wasn't quite enough in town to really invest the PCs with the import of their actions, and the warrens might be just a little long, but the final act is the right length and very, very evocative. 8/10.
P2 Demon Queen's Enclave
The highlight of the series, with great potential for roleplaying which became a lot of actual roleplaying. My group befriended the drow necromancer and the soldiers and wreaked havoc against the priestesses of Lolth, after first visiting them to see if they were worth befriending - they weren't, they liked the necromancer more.

P3 Assault on Nightwyrm Fortress
A disaster. It starts off well enough, going through the Tomb of Sartine, but then going through the walls of the fortress to reach the tower (or, rather, to find the keys to get into the tower) is forced, linear and dreadfully boring. There are some good encounters in there, but they're buried under the tedious length of it all. This adventure, more than any other one in the series, seems to have been hit by policy decisions that it should be possible to go through all the adventures as pure combat romps, and although P2 allowed roleplaying alternatives, they didn't survive into P3. Score 2/10.
E1 Death's Reach
The basic premise of E1 (souls being diverted to evil ends) is just too similar to P3, but the execution makes this one of the best adventures in the series. It's suitably epic: the group fight major forces aligned with Orcus, get to meet the Raven Queen (which was great, because as opposed to their normal brash manner, the group was completely speechless in her presence), and then go to a ancient battleground of the Dawn War. This one is setting up the entire Epic series of adventures, and it's a great start. The final act - the Reliquary of Timesus - is once again a little too long, but only a little. 8/10.
E2 Kingdom of the Ghouls
We've played one session of this one. Alas, it starts in Sigil! Argh! The link between E1 and E2 doesn't quite work, but I was able to salvage something. We'll see how this one goes. My PCs are very glad they have a cleric with them!
Cheers!