I've been lucky enough to play in some of The Elder Scrolls Online (ESO) betas. I had a lot of fun, but some people don't seem to like it. The main criticism I see leveled at ESO (other than simply "it sucks") is that it doesn't look or feel like a proper Elder Scrolls game. Another common criticism, is that it looks like your standard MMO. Both criticisms are to a degree true, but...
ESO is a compromise between two unique formulas: the MMO model, and The Elder Scrolls franchise. And after a handful of betas, I can tell you that it's a good compromise between those two formats. There are things about it I like, and things about it I don't. The graphics aren't as good as Skyrim, for one; the weapons are weightless; and combat is a little more restrictive (no dual wielding magic, or sword/spell). In this way, it feels similar to a replay of Oblivion.
And Oblivion is a great game, but it simply doesn't compare to Skyrim. Of course, why should it? Oblivion is basal. It came out almost eight years ago. And if The Elder Scrolls Online was The Elder Scrolls VI, I'd agree that these almost entirely cosmetic issues are a step backward and that the quality of the game did not merit much more than twenty of your hopefully hard-earned dollars.
But ESO isn't TES 6. It's The Elder Scrolls Online. And it requires compromises from the normal TES experience, and it means favoring performance over aesthetics. When you're running around a dungeon in first person mode, it feels very much like a TES game, with the caveat being that it feels more like Oblivion (with a sweet texture mod) than it does Skyrim. When you're running around in the world, it feels very much like an MMO, and it feels like a good MMO. At present, it looks better on a 22" monitor than on my 39" Samsung.
The class system is another compromise that had to be made, and they did a great job. There are armor/weapon/race combinations that are going to benefit one class over the other, sure. The spreadsheets will tell you that if you're going to make a Sorcerer, make it a Breton who wears light armor and wields a destruction staff. A Redguard with heavy armor and a 2hander works just as well, though, with the right spec. If you want to play an Orc Templar (the healing class) who wears medium armor, sneaks around, and dual wields, go for it. I bet with the right combination of abilities, you would be terrifying. An assassin with heals. Think about it.
Truth be told, my biggest gripe is that I can't go into King Casmere's bedroom, rob it blind, then mess up the place. Spilling cheese wedges and apples everywhere. Flinging plates at the wall. Leaving a sweet roll on his bed. Because let's face it, that is the most fun aspect of any Elder Scrolls game. At one point during the most recent beta, I caught my friend trying to smash a table with his two-handed hammer. He said he was trying to knock everything on the floor. It was the saddest thing I had ever seen.
So ESO won't be a perfect game. It will never be a perfect game. I hope I don't have to explain why that is. But it will be damn good. It's fun as hell. If you want to play an innovative new MMO, give it a try. The blend of TES and MMO traits is well executed. It will be worth your money. But if you want WoW 2.0, skip it. And if TES VI is what you want, then save your money. You simply can't do enough solo to completely replicate the experience of a traditional TES game, but it comes pretty damn close.