I'm playing in the campaign on the weekends, and our party is just about to finish "Haven of the Bitter Glass" - just about middle of the Paragon tier; in fact, we hit level 14 last session.
I'm quite enjoying the adventures, but I tend to prefer combat, so there is that consideration. I would say that the battles are really solid throughout the campaign - the second part of the Adventure Path had some of the coolest battles I've been a part of; and the end of Heroic Tier and the end of the first section in Paragon were really tense and fun.
The first couple of adventures have some built-in hooks to draw the players from one adventure to another, but without much of a overall story that is revealed. There are some well-documented retcons in the early adventures too, so I think it is a really good idea to read all the way through Heroic tier before starting to run the Adventure Path at all. So far in Paragon, it feels like the adventures are made to be more free-form, with a quick mention to the DM about the overall story - without the DM doing this work on their own, it doesn't feel (yet) like the paragon tier is connected.
I have been running some players through the campaign myself - we are on the 4th adventure now. I had the benefit of preparing some of the links for later on, and I think my players are feeling pulled into the story. I focused on building up the city of Overlook, planting NPCs for the players to care about, and seeding the area with potential alternate adventures. The other adventures were not really worth doing, since the Adventure Path covers every level progression, but making Overlook feel like home has been a big success, and WotC did a great job in "Siege of Bordrin's Watch" of creating the city and giving us NPCs - it made it easy to build on that. At this point, I could easily see using Overlook in a new campaign.
For linking the adventures, I would suggest looking at the Heroic/Paragon crossover adventures ("The Temple Between", "Beyond the Mottled Tower") and planting foreshadowing from the last fights in the third adventure ("The Shadowrift of Umbraforge"). Umbraforge should also be used to foreshadow "Den of the Destroyer", and familiarity with Umbraforge will give you the tools you need to tie "Bordrin's Watch" to it. "Lost Mines of Karak" needs extra attention to make it fit into the campaign, check out the middle Paragon adventures, and be careful to read the DM sidebars in that adventure - it should be made clear to the players in this adventure why all of this is going on. "Rescue at Rivenroar" is the biggest challenge - there are things that are important in later adventures that can easily escape the players' notice. Use the wiki heavily for this adventure - the combats are good for level 1 characters, and the skill challenges can be really good, but the mix of monsters used are a bit flawed, and balancing extended rests with the quest is all on the DM.
