So far I've been having tons of fun with Morrowind(5 days/15+ hours). Dungeon Siege has taken a permanent back seat and will probably never be loaded again. I do miss being able to scale buildings and the city walls like in Daggerfall, that was nice. I think if you have an older system you should hold off until you eventually upgrade. It wouldn't be nearly as fun with low framerates and most graphic options reduced.
If you've played Daggerfall you pretty much know what you are getting into.
The scenery and cities are beautiful.
The character animations are severely limited. I never use 3rd person view, the PC animation really pulls you out of awe struck mode and places you into mid 90s tomb raider mode.
The game is smaller and more focused than Daggerfall. Which IMO is an improvement. It is still the most open ended CRPG out there, though.
So far the quests have been fairly varied and fun to complete. After I put in some more hours they may begin to become repetitious. I'll have to check back on that one.
It does kind of suck to have to switch to "magic hands" mode to use racial traits, star sign abilities, and magical weapons spells.
And yes, the quest journal could be MUCH better. In a game where you can easily have a dozen or more open quests at a given momemnt the journal provides the absolute bare minimum.
I think players willing to play thieves and assassins will have a lot of fun because there are plenty of opportunities to practice these skills and you aren't forced to follow the path of the Avator or any such thing.
Hopefully, we will not have to wait 5+ years for another great CRPG from Bethesda Softworks.