I've got mixed feelings about it.
The game is level scaled, such that you can go anywhere in the open world at any time. However there appear to be something called "champion points" which are gained after reaching the level cap, and which are required for the game's most difficult content. So, maybe progression isn't entirely pointless.
Aesthetically, it's not the worst but leaves something to be desired. The environments look fine, but aren't as atmospheric as Morrowind or even Skyrim. The armor models I've seen are pretty ugly, and characters have an uncanny valley thing going on. Normally I play girls because I wish I was one, but I couldn't make one that doesn't look like a tranny or burn victim so this time I'm playing a man.
The combat is more action-y than most MMOs, but seems to be missing something I can't quite put my finger on. Attacks feel like they lack impact - though this might just be an issue with destruction staves, which seem to be the only real weapon choice. This is because you're supposed to put all your level up points into either stamina or magicka, which not only increases that resource pool but also the effectiveness of skills that use it. Almost all skills you get from your class use magicka, but all weapon skills except those of staves use stamina. So you go staff, so you can use both weapon skills and class skills. You can only have six active skills equipped at a time - while I'm not a fan of piano-playing with dozens of keybinds like in WoW, a mere six skills is going too far in the opposite direction.
Another thing that annoys me is the lack of an auction house. There are player-made trading guilds that rent merchant NPCs, and being a member of such a guild seems to be the only way to sell stuff without annoying everyone in zone chat. Another problem is that you start out with just sixty inventory slots and sixty bank slots, which are quickly filled with crafting materials you may or may not ever use; there's no weight or size limits, every type of item takes one slot. So, you'll frequently find yourself having to go back to Vivec to sell, fence, deconstruct or bank the stuff you pick up, which gets old fast.
It's not all bad though. I have yet to see a typical "kill ten rats" quests; instead you have the kind of quests you'd see in a proper Elder Scrolls game, with actual plots and multiple objectives. Some of these even let the player make a choice, and some involve stealth (which everyone can do) in addition to violence.
I'm playing the Morrowind expansion which starts new players off on Vvardenfell, and have yet to visit other zones. Vvardenfell seems much smaller than it did in TES 3, and not just because the draw distance is more than 15 feet now. Still, I'm enjoying the exploration and questing. For now, I'm going to keep playing and see where the journey takes me.