Mmm k. So I tested this out on a work computer that had Windows 7 64bit. Funny thing is, I actually do have Windows Xp 64bit installed at home which runs my Oblivion. Anything I should know that would be beneficial to Win xp 64 using this or Oblivion Stutter Remover?
The short version is, if you are using LAA on a 64 bit windows with OSR heap replacement, then you can turn up iHeapSize (if you don't have LAA then turning up iHeapSize may cause Oblivion to refuse to start). And if the above applies and you are using specifically windows XP, and your Oblivion allocates enough stuff on the heap that it could benefit from LAA, then turning up iHeapSize isn't really optional, it's basically mandatory. The point at which you need a larger iHeapSize on XP will be really obvious, you'll play for a while at normal speeds and then Oblivion will suddenly have a dramatically slower FPS and start stuttering a lot.