I mean, isn't vanilla New Vegas pretty famously unoptimized? I think its performance has less to do with your hardware and more to do with the engine (hence this mod).
My toaster of a desktop can easily run the game at pretty good framerates yet the game just sometimes decided to just crash like it's nobody's business.
Hell, it ran it just fine before getting an upgrade from 4gb to something like 16gb of ram, but the problem wasn't performance issues. Instead it was random crashing. Mods completely fixed that issue.
New Vegas is a pretty good game, but I wouldn't wanna play it unmodded because I don't wanna deal with random crashes.