Played through the demo a few times. I don't think this is a bad port at all. Framerate isn't 30fps but it is pretty stable and smooth enough to be playable. It's a bit disappointing but not a deal breaker for me. Controls are fine with CPP, not so much without it. My main complaint is the 3D->2D transition when changing to FPS aiming. It isn't the loss of 3D that bothers me, but rather the quick shift in focus from 3D to 2D and back again to 3D when exiting FPS view. I think it was starting to give me a headache.
Hard to believe the framerate will improve much between the demo and the final build, but it would be a pleasant surprise if the game could hit 30fps.
Someone on 3DSForums claims to have gotten the game early and posted an impression stating the that framerate has improved and that the visuals are noticeably better then the PS2 version. This goes in line with the review statements.
He/she hasn't posted pictures or anything though, so I wouldn't take anything from it just yet.
Hard to believe the framerate will improve much between the demo and the final build, but it would be a pleasant surprise if the game could hit 30fps.