You won't notice the difference most of the times because the difference is not occurring so often, and it's right on the limit.
Thing is, I've dropped Window's paging file system from my Win7 64 bits like two years or something ago (almost from the beginning) and had only 8 GB of mem, and never felt the need for any more memory..
.. until I've started play Il2CoD on maximum settings. Now and then, specially in the few MP sessions I've had, and having opened Google Chrome with lots of tabs in background, I've got a few Windows Low Memory warnings.
That's the reason I've went from 8 to 16 GB. Of course, I never had them since then