I had more or less given up on 4E after running about half a dozen sessions, but threads like this are helping me come around to giving it another chance.
I think that I actually very much like 4E. It's the way that the published adventures are written that I don't like. Even the better ones (The Slaying Stone, Reavers of Harkenwold) make it very easy for the game to play out as a series of mostly-unavoidable combat encounters with short breaks for role-playing and exploration. Running an AD&D 1e session through the start of N1 Against the Cult of the Reptile God made me realize this; had we been playing with 4E rules, the session would have played out very much the same, except the one significant combat encounter would have been a lot more fun and two players would have had a lot more to do during the battle.
I love how 4E makes it that it's not a huge stretch to find ways for every player to be involved in the game at virtually all times. In our 4E games, there was never a situation where any players felt that they couldn't contribute something worthwhile.
I love that the 4E DM's Screen doesn't give me a headache just looking at it, unlike the AD&D 1e and 3.x/PF screens. I look at those and my eyes just glaze over.
I love that we spent very little time looking up a rule when playing 4E; the base rules are mostly easy enough to remember, and everything else is right there in a power or monster description.
I love how 4E makes it fairy easy to reliably judge how difficult a combat encounter will be, and how there are clear guidelines for scaling the encounter up or down.
I love how players in 4E are much less likely to end up sitting out half the night because of a couple of unlucky die rolls.
I'm still frustrated by many of the overly fiddly bits (until the start/end of next turn condition/effect/trivial bonus tracking and the ubiquity of temporary hit points in particular), but think that I might have given up on it before the new rules became second nature to me. There is a lot to love in 4E.