I got the game for PS3 and these problems are blown way out of porportion by a few handful of reviewers.
It has like 20 reviews or so and no one mentions this crap except IGN AU and Lens of Truth.
So far I have been playing for 6 hours. It is great fun and way better than the first.
The graphics look nice, Ezio moves smoothly from place to place, and nothing much to complain about.
Even Kotaku.com reviewed the PS3 version and they found nothing to moan about.
AC suffers from the same problems that many sandbox games have. It has screen tearing, pop ins, and minor frame rate problems. So did GTA 4 and InFamous. Did that stop them from being AAA quality games? Get over yourselves, PS3 version of AC is AAA.