So far, I rate the first six adventures as follows:
H1: Keep on the Shadowfell - a very good adventure. The initial stages of the adventure work really well, and you can become very attached to the townsfolk as you travel to and from the adventure areas. There's not enough development in the final section of the dungeon, though, and the final villain hasn't been foreshadowed enough. 7 out of 10.
H2: Thunderspire Labyrinth - a good adventure, but potentially more challenging to run than H1. The home base can be really well developed and utilized by DMs and is excellent. Less fun are the duergar, and the links between the sections of adventure, while they work, don't really build up into a great final showdown. 6.5 out of 10.
H3: Pyramid of Shadows - great backstory, but the entire adventure just doesn't work. It doesn't help that there isn't anyone you can trust in the entire adventure. There appears to be the potential for roleplaying, but it actually doesn't work very well. A disappointing end to the Heroic Tier. 4.5 out of 10.
P1: King of the Trollhaunt Warrens - a strong story, which is somewhat sabotaged by the characters coming out of H3 and not having strong ties to the region they're meant to save. The warrens are nicely presented, and the final act in the Feywild works very well. 7.5 out of 10.
P2: Demon Queen's Enclave - a strong story, and it gets better with a host of factions you can actually interact with meaningfully (which is not the case in H3). It's a pity that the final encounters are somewhat linear: it would have been nice for more outer-planar exploration. 9 out of 10.
P3: Assault on Nightwyrm Fortress - a great premise, but lacks good characters to interact with and puzzles to solve... and places to explore. It's an occasion where the "only important locations" fails: the walls need more detail! Some nice encounters, but not enough to redeem a disappointing end to the Paragon Tier. 5.5 out of 10.
Cheers!