None of them are perfect, but it seems to me they did a better job with the casters than the noncasters. The casters have at least distinctive mechanics, which are reasonably simple. The individual spells (cantrip magic missile?) need some work, but they look like D&D spellcasters, and they are meaningfully different from fighters.
The fighter and rogue on the other hand, are not good at all. Sneak attack is just as dumb as it was in 3e. Cleave is just as dumb as it was in 3e. Per-day abilities pop up in both and the fighter (though not through a class feature) has a damage-on-a-miss ability. They seem to have taken the "worst hits" of 3e and 4e versions of the classes and stiched them together. On top of that, skill mastery looks overpowered, tools of the trade makes no sense and appears to be miswritten, and thieves' cant and thief hiding are decent concepts but poorly written. Weapon focus seems like an automatic choice, which is inadvisable. I don't know that there's a well-written class ability between the two of them. Not good.
Edit: Good question. I was obviously talking about the playtest versions. If you ask what classes I like in general, I favor rogues slightly and disfavor clerics slightly but I like all of them pretty well.
