[quote name='mywhitenoise']It's just The Pitt add-on that has the major freezes...at least that's what I've read, I haven't tried it myself yet.
I haven't played any of the add-ons yet (don't know if I will), but I played everything up until that and completed the game with maybe 4 or 5 freezes total.[/QUOTE]
For me it was FLAWLESS during the main quest. As soon as I finished the main quest and launched into Broken Steel it would get laggy(like 30 seconds of freezing then would slowly go back to normal) or would hard freeze required a restart of the PS3. This occurred during ALL of the DLC (Broken Steel, Point Lookout, The Pitt, Operation Anchorage, and Mothership Zeta).
Now, perhaps if you play the other DLC BEFORE finishing the main quest and doing broken steel, you won't have the problems. The thing is though I found most of the DLC pretty damn hard so I wanted to level up more than the level 20 the main game lets you. Great game and still worth playing but I'm very glad I was able to sell my copy for around 40 bucks!