I have basically third world internet and a much slower Hard Drive than the default PS3 Hard Drive. I don't have any of these problems.
The only game breaking thing I've noticed with the Playstation 3 version is the Notorious Monster FATEs are almost unplayable when more than 20 or so people are involved. The monster and players all start disappearing. It's a mess.
Behemoth is especially bad. I saw him maybe twice, for 10 seconds a piece the entire fight. And I was in the Zone when he spawned. Ridiculous.
