Don't forget about the greater likelihood of crashing when our systems are overheated. I love marathon sessions but I think I'm seeing a real difference if I limit my time to shorter sessions. It's hard but so is losing data in between saves.

That was
very true on our old 60GB Fat.
Since my better half brought home a new 160GB Slim, overheating hasn't been much of an issue, and we've definitely seen fewer freezes. In fact, we've both been able to complete several playthroughs.
However, even with a brand new system, there are just some places (Camp Hope being the worst, for us) that stutter and drag and freeze. Also at the top of our experience lists are Bitter Springs and Red Rock.
What's funny (in an ironic way) to me is that I've read over and over how the game engine is to blame.
Well, while the b/f has been hogging NV on the new PS3, I've been putting crazy marathon sessions in to FO3 on the old 60GB and I've yet to experience a single freeze or crash. Honest,
not one. Now, I'm not exactly the swiftest horse out of the gate and what I know about computers you can fit on the tip of a needle. Still, it seems to me that Obsidian will, eventually, get this freezing/crashing problem licked.
However, I think that is going to depend on us (the players) reporting issues honestly and without hard feelings.
The more Obsidian learns about areas that cause problems, the better able they will be able to go in to those areas and find ways to at least ease said problems, if not fix them entirely.
As for this current patch, the better half and I have both seen improvements.
He's overjoyed about companions showing up on the map, the way recipes are now ordered at the tables and campfires and that armour at the NCR safehouse.
Personally, I was overjoyed to find that ED-E had been not only "fixed" from his "don't follow/don't fight" glitch, but his weapon upgrade was
actually an upgrade. He is now, officially, my favourite companion! He doesn't whine and moan like the others and he is a beast when it comes to watching my back.
Does the game still have problems? For the PS3 ... certainly.
Did the patch improve things? For the PS3 ... definitely.
At least, in our experience.
:)