The PS3 currently only outputs 480p, 1080i or 1080p for Blu-ray, so if you don't have a 1080p TV or a 720p tv that doesn't handle 1080i well, then it might not be the best option. Possible updates could give it 720p output.
The Sony player does do 1080p24, which I hear is suppose to be better if your 1080p TV supports it, the PS3 can't do that as far as I've heard.
The PS3 doesn't come with a remote, and the remote you can buy is bluetooth only, so the PS3 doesn't have IR. This means you are forced to use the bluetooth remote without the ability to integrate the PS3 into a Harmony remote unless it was a real expensive one that supports Bluetooth.
I think the PS3 is pretty silent, so that shouldn't be an issue. Though, I've had two lockups on mine with the last 3 films I've watched. Though, the PS3 probably starts up faster, but I haven't checked reviews of the Sony player.
The Sony player would give you more display info on the face of the player, while on the PS3 you have to hit select to overlay the time and other info on the screen. If that's important.
I don't know if the Sony player has 5.1 analog out if that's the only way your receiver can get higher quality sound, unless you have a newer compatible HDMI receiver for the next gen sound.
Thouse are some things off the top of my head.