I was a bit of a naysayer myself, leading up to the game's release. I wasn't terribly confident in it. But I've been proven wrong, to an extent. While I wouldn't say I prefer it to Morrowind or Daggerfall, I'd say it's definitely a step up over Oblivion and is a full out realization of what that game could have been. So far there seems to be less hand-holding and more immersion. The balance isn't terribly good but I don't think Bethesda has ever released a game that has been well balanced so that was more or less expected.
But I do miss classes. I find that the lack of them actually makes the game less immersive and enjoyable. It's annoying from a gameplay perspective, because it means that I can't really have certain skills lined up from the get-go as areas my character specializes in. I don't like it from a role-playing perspective, either, because it makes it seem like my character has been sitting around pursuing a balanced assortment of tasks his whole life. I'm not sure what sort of upbringing could have led to equal proficiency in PIckpocketing, Two-Handed Weapons and Restoration magic but it takes me out of the game a bit.
Sure, people say that classes can be limiting (which is and isn't true), but even just a Fallout-style of tagging a few skills that you may have worked on beforehand would be cool.
I know it's a minor complaint, and I really do enjoy the game. But as the classless system was something that, IIRC, was much-touted, I wonder if anyone else feels the same way.
On the other hand, I do like the replacement for the Birthsign system.