Besides, after getting the platinum trophy on Fallout 3 GOTY I'm used to Bethesda's clumsy ports.
I'm glad you brought this up, I owned Fallout 3 (on PS3) both the vanilla version (which I sold) and the GotY edition (which I still have) and I can't believe that even with the annoying bugs in the original version they managed to introduce new system crashing bugs as well as major slowdown into the title with the GotY addition.
While I could predetermine when it would crash on me in the original version, the GotY was a crap shoot, making me replay countless areas one after another. Also for the most of the time I played I HAD to look straight at the ground to keep the frame rate at a decent level, I could not use VATS without the game hard freezing and locking up, if I hadn't paid $30 just to play the add-on content I wouldn't have bothered and traded back for my vanilla version.
My biggest gripe is that Bethesda can't be bothered to patch the games after the fact, I know that takes resources away from development, but that goes hand in hand with supporting your customers and providing them with a functional product that is as error free as possible.
After feeling like I played the same game, all over again when I played New Vegas (when looking at Fallout 3), I might either wait till the bugs are patched on PS3 (I prefer the controller, even though I can play it on X360 and PC) or just skip it entirely, I think I've spent enough time in Bethesda's Oblivion (and the Shivering Isles expansion) and Fallout worlds that I don't really feel like spending more time in another glitch filled world that I might not enjoy as much because it isn't all that different from its predecessor and be constantly reminded how much the bugs make me mad and ruin an otherwise enjoyable experience for me.