Alright guys, I just stumbled on a tweak that I'm calling a miracle. It may not work the same on all systems, but on my i7 rig it has transformed everything. It's very simple, and with it I'm able to run EXTREMELY DENSE autogen at default levels, meaning DEFAULT max per cell values, with NO STUTTERS of any kind, totally glass smooth, and no blurries.
Depending on the area I am able to do this at a full 25-45fps, never going below 25. I've tested this with and without the new fps limiter utility, and I am getting best results WITHOUT it.
The tweak is to use UMLIMTED frame rate, and set a BUFFER POOL value of 200MB-300MB. The Buffer Pool is what makes or breaks stutters on my system. You will need lots of video RAM for this, though on my 900MB GTX260 I am able to run 300MB, and also use 2048 non DXT5 clouds, 8xS supersampling, and 16xAF at 1600x1200 with no impact on performance.
The shots below show Extremely Dense autogen with no max per cell tweak in use, and the flight was glass smooth, unbelievably smooth. The urban shots are running at 25-27fps, and the rural shots are running 30-40fps. If I drop Buffer Pools back down to 100MB for example, the game becomes and stuttering mess and absolutely unplayable with this kind of autogen.
Give a 200-300MB Buffer Pool a try and let me know how it goes. It works well in combination with the fps limiter utility since that too uses unlimited framerate, but I was getting faster frames when starting without the modified bat.
I simply can't beleive I'm getting 25-40fps in these scenes with not a single stutter.