Please read the whole post, and please don't take it personally, really didn't mean to post this info as a personal attack on your efforts, quite the contrary, if you read my whole post you'll notice that
About the tweaking for both systems, yes, as I pointed out there are tweaks that will work for ppl with both brands of video cards (and please note that in my post I didn't mention specific graphic card related issues).
What I mention though, is that there are some memory tweaks that will help ppl with only 1 GB of RAM as you say you included in your .ini, while there are tweaks that will greatly enhace the performance for ppl with 2GBs of RAM, like "uInterior Cell Buffer", "uExterior Cell Buffer", "iPreloadSizeLimit" or "bPreemptivelyUnloadCells" which may have different values for ppl with more RAM.
There are some other tweaks that improve the framerate on HT/Dual core systems, like "bUseThreadedBlood", "bUseThreadedMorpher", "bUseThreadedTempEffects", "bUseThreadedParticleSystem", "bUseMultiThreadedTrees", "bUseMultiThreadedFaceGen" "iNumHavokThreads", "iThreads" and "iOpenMPLevel". While this may improve performance on some systems, they will also cause instability in other systems as well, dunno if you included them in your .ini, but that's precisely my point, some ppl may be loosing the chance to have better performance if you didn't, but at the same time, some will have instability issues if you did, you get me?
About the max frames to render ahead, I've read many threads on the Hardware and Software Issues section of the Official Elder Scrolls forums, and most of them agree on what I posted above, in fact, don't take it from me, take it from the tweak guide for Oblivion if you want:
http://www.tweakguides.com/Oblivion_13.html
Anyway, as I mentioned, I know you're doing this for the greater good of many users, and I appreciate it, it's just that in some cases it may cause more harm than good, read this quote I found at the tweak guide for Oblivion for an example:
http://www.tweakguides.com/Oblivion_10.html
As I said before, I apologize to you for pointing this out, please don't take it personally, in fact, I appreciate the time and effort you invested in your .ini file, but I also know that after reading this post you'll fully understand my point of view.
Peace