Firsty - I know that a lot of people have had big problems with the lag on this game so people are going to be wary of that when they buy it but what you should know is that THERE IS A PATCH COMING THIS MONTH (JANUARY) THAT THE COMPANY HAS SAID WILL FIX EVERYTHING.
Anyway i havnt had any problems and im ashamed to say ive spent 110 hours on it. Thats probably the most hours ive spent on any game considering I dont consider myself a "gamer".
You will get completely lost in this game and the annoying/good thing about it is that you will try and play the main story but then get sidetracked by 10 hours because you've found something else to do! The game is huge, ive played it for a long time and stil havnt found/been everywhere and still have no where near done all the storylines.
The other unique aspect to the game is that you can be whatever you want to be and be better at whatever you want to be better at. I.e. upgrading your magic and being a beast at that instead of using weapons.
If you want a good game where you can improve your character and find all sorts of cool weapons and explore for hours then get this.
P.s. the graphics are awesome