I usually play through once w/out mods myself.
With the exception of DarnUI. Which is still a WIP. This, IMHO, is a must have have for the PC version and how FO3,FONV, and Oblivion should have been in the first place.
As far as the .dll fix, Im a bit cautious about that one. Isn't there already a DX9 file on our systems we can use instead?
I too get the stutter on occasion. But that has been present, at least for me, in Oblivion and FO3 as well. I think its the nature of the engine.
That or a ATI issue w/the engine, Im not sure.
My game is on a Vertex SSD as well, so you'd think that would solve some of the hitching/stuttering issues but it doesnt. it helps overall, yes, but not for that stutter issue.
For those curious about other methods, The best fix Ive found is the stutter remover plug-in for FOSE.
Unfortunatly, it isn't out yet for NV and will likely be after Bethseda gets the game stable.
Since it requires STEAMS co-operation to mod the encrypted executable, which they will gladly help with.
But each patch requires a new update, so might be a while.
I think at, or around the area or Primm --- little after, the game really started getting a lot better for me (enjoyment wise)
I'm running around w/Cass now and she has some funny banter in fights at times
I read this on the official forums and it helped some for me.
Lowering the Water Multisampling to Low, Relections Medium helped.
Shadows, Actually turning these up helps, Oddly. Max Shadows, High Quality, but Medium Filtering.
Although the stutter is still there, it seems to be a bit better.