The thing about D3 is that people are comparing the classes there as if they were MMOs, due to there always being "that one class" that's just useless and needing buffs or nerfing other classes just to make it more even with the suck. Diablo has never really been about character advancement in the sense it is in an MMO or RPG. You just wanna level up so you can get more powerful and unlock different abilities so you can just obliterate everything in your path. Therefore, imho, anyone complaining about class advancement and character building this early is just bitching. Every class is fun, trust me. D3 wasn't developed to be like Mass Effect or KOTOR, where there's a big, deep story and you can really get into roleplaying. No. The story is the exact same it's always been: Diablo's back in yet another incarnation and you have to slay all his minions to get to him, while picking up loot along the way. That's it and that's all it should be.
Also, you can only play each class for a few hours in beta, or at least until you finish the first dungeon (a good 4-5 hours or so...not bad); then you have to go back and start all over again if you wanna try a new character. I'm completely dumbstruck how anyone could say a particular class "sucks" when you can't get past the first few levels in beta.
Talkingbackwards, you know me. You know I don't like following the herd of neither naysayer nor apologist. I make my own opinions about games and have no problem having fun where others are bitching. Therefore, when I say D3 is a blast if you like Diablo, then it's a blast. You must, however, keep in mind that it's DIABLO; they're not trying to re-invent the wheel. When I played the beta, I was like a monkey fucking a football; drool was coming down the side of my mouth, body odor perforating the room due to not leaving the PC, and regular shouts of, "HOLY SHIT THIS IS AWESOME!"
To me, it will be GOTY alongside Skyrim. It picks up exactly where D2 left off in terms of gameplay, but with much needed graphical improvements (but without losing that Diablo "feel") and a few new leveling mechanics that I really enjoy. Like I said a few months ago, gone is the, "Ok, you need to get to 50 ASAP...GO!!!!" There are ability unlocks with every few levels, such as being able to wield multiple spells/abilities in your spell/ability bar. You have to earn that by leveling up. Sure, it's a small, seemingly insignificant thing, but it adds a little something to work towards. Honestly, the few hours I've played the beta have made me hungry for this game. Don't spoil it by over-analyzing it or listening to people bitch about it. Make your own judgement because I think you'll love it if you like Diablo.
Maybe this will set the record straight: when I played D3 for the first time in beta, I felt like a teenager playing Diablo all over again. It's just FUN. If you remember that feeling the first time you played Diablo and loved it, then you won't be let down.