I had initially planned to run the playtest using Ruins of Undermountain, but had a hard time finding a good map and we ended up being fairly cramped for space, anyway. I resigned myself to the playtest adventure again, this time with a better head for it after having blundered through a bit of it during the first playtest session. Since everyone also showed up late, we just plowed through barebones character generation as fast as possible (so fast, in fact, that I forgot to give the guy playing the rogue another background).
The players liked most everything about what they saw--especially the sorcerer, warlock, combat speed, and checks--with the exception of wizard spells (of course), hit points, and armor. Though two of them also play 3rd Edition (as well as 4th), none of them like pseudo-Vancian magic. They also felt that hit points were a bit on the low side. Personally I think that given most monsters have attack bonuses of +0 to +2, that despite a lucky hit having a decent chance of taking someone down they are fine.
As for armor, the fact that the rogue had a better AC than the fighter irked even the rogue player. 500 gp for scale armor is pretty steep (again, silver standard?), and I think that there should be more granularity to armor (like, more shields), as well as a system for resisting damage on the heavier stuff. This would require revamping resistances, which I also think they should do. At the least give the fighter benefits for having it, as well as put other options in the starting price range.
Anyway, with the exception of the wizard we are largely still enjoying the playtest. Here is hoping that we do not have to wait three months for the next packet.