I just finished it on Saturday, I've also finished 1 and 2 on PS2.
For anyone that has played the first two, it really is more of the same.
The visuals are stunning, the backdrops are just awesome and you really get the feel of the whole storyline. The monsters look great and everything just blends in nicely, it really is a joy to look at.
The gameplay is more of the same, plenty of combos and button mashing mixed in with some puzzles (although pretty easy IMO) and some big bosses that require a bit of work.
Again as you work through it you get different weapons and different magic, they look vastly different but you do tend to find yourself doing the same button mashing with either of the weapons.
However as with Part 2, I found my interest in the game waned once I was about halfway through it, I still stuck it out till the end but by then if felt like a chore. The game does seem to get a bit repetitive and it is very linear. Also, I don't think it has much replay value, in fact I have mine listed on Ebay now as we speak.
I think it is worth playing simply for the visuals and the gameplay is nice, I do think though that the game gets a bit boring after a while.
I bought Red Dead Redemption yesterday, moving onto that now, can't wait to crack it open!!