Maybe I can help.
Both of the 3.5 campaigns I was in died under circumstances that angered me and probably colored my perception of 4E. The first ended during the last battle with the last bad guy, in the last session of our last 3.5 campaign. That was how the DM billed it because he was going 4E (he owns a game store so he rightly would prefer to support the current game system). It was a near Total Party Kill because of 2 players being _____ ____, blowing everyone up (fill in your favorite curse words). 1 character survived and thus we ended the game, with a hand wave as far as I was concerned. I nearly got up and left the table but I didn't.
My other campaign was Savage Tide and it ended because one of the hosts wasn't having fun anymore and we'd already had to hand wave the bad results when he went berserk and randomly stabbed some NPCs. He wasn't having fun because his 6 INT fighter wasn't any good for coming up with strategy.
Now, I'm also someone who likes the versatility of wizards and clerics. Thus, when I started looking at my options in 4E, I was not impressed.
In my thinking, the 'at will' magic missile spell has essentially become the wizard's crossbow (I first read that comparison here at ENWorld).
Perhaps a house rule that you could spontaneously convert another use of a power into a Healing Word or something would make me like clerics better.
I understand the want to balance classes so everyone has fun, or really nobody is left feeling useless. Unfortunately, I really just see everyone as a -warrior- with powers that do different things and have different names.
Rituals don't impress me (Rope Trick is 12th level?!).
And I don't like 30 years of canon being thrown out.
However, for the time being, if I want to game with my friends, I have to play 4E. So, what do I do?
Well, it is now a far more social event for me. I show up to hang out with friends, share a beer, and swap memories. Don't ask me to take notes, because if I do, they might be mistaken with notes I didn't erase from 2 sessions ago.
I also think that 4E could be useful for casual gamers who don't learn important things like what their spells do and want to run complex characters like a 3E druid. I use this specifically because in our Savage Tide game the other host (they were husband and wife) was playing DnD for the first time and she was a huge time sink, continually forgetting what her spells did, forgetting about her animal companion and other stuff. She was the star of the party (druids in STAP rock), but her character was more like a communal entity we all shared responsibility for.
Not sure if I have anything else useful, but I need to do more Christmas shopping so I'll check the thread again later.
