Player's. The longer the game is, the harder it is to replay it. Fallout was perfect in this regard. Fallout 2 was way too long. It's subjective, of course.
Definitely agree that Fallout 2 was too long, but always felt like Fallout was a bit too brief. I guess I'm saying that I generally felt a middle-ground would feel like a more appropriate length, but I'm the type that if I'm going to replay a game - even a highly replayable one - I'd want a bit of time away from it before I did, rather than hopping right back in. So I guess that informs my opinion about it too.
Anyway, it is what it is. I guess you can consider this a form of feedback in a way. Not too sure if I'm in the minority or not, but I am one who also wished AoD had been a bit longer.