Its an issue with the shared memory system that the PS3 uses. Related to the slowdowns that many PS3 users had as their save file grew.
If you are going to get another version, I would recommend the PC version if you have the hardware to run it. The upgraded graphics and Steam Workshop alone are worth it. I had the PS3 version when it launched, and have since picked up a PC copy (Love the Steam sales)
Hopefully in the next year or so I'm looking to build/buy a sweet desktop, but as of right now it's not an option. I do agree with you though, PC would probably be the best way to go, if it were possible for me right now. No way could my laptop do it justice.