For anyone who's still trying to decide PS3 or X360 version to get other than importing the previous game saves.
I rented PS3 to see how well the game plays compared to X360 version. Overall, the problems on PS3 version doesn't prevent you from enjoying the game but if you have the option to get ME3 on X360 (or PC), don't get the PS3 version. PS3 version only has two advantages, single disc and free online.
Here are the cons of PS3 version:
1. Whenever there are 2 persons closeup especially cutscenes, the framerate gets bad, like around 10 fps.
2. Since it has no option to install any data to the hard drive, the load time is slower.
3. There are more random graphical glitches like during cutscenes "skip" around. I guess using ME3 beta engine on ME2 on PS3 still didn't give Bioware time to fix it or they just don't care? ME3 on X360 also has similar graphical glitches, just not as often as PS3 version.
4. Mostly at the later battles on Earth, there are a lot of different sounds mixed together. On PS3, there are more audio cut outs.
5. Loading the Save or Load menu is slow. Same problem with ME2 on PS3.
6. Overall during the battles, X360 version feels smoother than PS3 version.
7. No unlock for Avatar's Shepard helmet and omniblade.
8. If you manually copy the ME2 game progress save file only to another PS3 console but same PSN ID, I don't think ME3 can import the ME2 game save. It's because a lot of unique game progress info is store in the game profile save file. You'll need Cloud Storage to move the game profile save file to different console. (I didn't have time to figure out if there's trick such as import ME2 game save to ME3 on the console that played ME2, then save ME3 game after it started, then copy the ME3 game progress save file to the new console without Cloud Storage. If this trick works, you want to do it immediate because special info such as Overload counter, game completion count, etc are stored in the game profile save file.)
Since none of the issues/bugs above are considered "critical bugs", not everyone will see them. Simple reason why the bugs exist, not enough time spent testing because not every tester will see every time.
The best part EA/Bioware did with cross platform games like ME3 is the Galactic Readiness % shared between PS3 and X360 (don't know about PC) as long you use the same email address for the Online Pass. But the individual player's ranking and characters are kept separate.