There are more problems than the graphics and controls. My main problem with the graphics is that there are some severe FPS drops later on when there's a lot of enemies on screen. Even when you're not fighting, in some sections. For example, in "Part 2" in the Northern Plains there are enemies that will fight each other. I was across the map (which is moderately sized) and I was still lagging badly and the graphics were grainy even though I had absolutely nothing to do with the fight between NPCs on the other side.
Also, the pacing is horrible. The story goes from required fetch quests to backtracking through those same dungeons over and over again. Every dungeon in the game is explored at least twice, with very few changes in-between each visit. The side quests are abominations and are the worst kind. They're all fetch quests that require backtracking and/or killing hundreds of enemies for items. I think one quest took me 3 hours of killing to get enough drops for.
Other than that, both the enemy and ally AI is very bad and the lack of any true "quick travel" really hurts the game. Even when you do get access to a ship for faster traveling, you still have to walk through large open areas filled with enemies to reach the town you want to visit.
I know exactly what you mean with the slowdown, the music almost came to a screeching halt as I made a mad dash for the nearest (no pun intended) save point out of fear the game was crashing and I had not save in a good while.
I'm not too sure if I agree with you on the pacing though, you could easily ignore the side-quests and chew the meat and potatoes only. The game had some really beautiful set pieces and the music made me not care about running through a dungeon the second time. All I know is that I couldnt put the game down because I always wanted to know what was going to happen next, which to me, meant the pacing was fine.
No quick travel kinda sucked but you run at a maniacal pace so that didnt bother me too much either.