USA Terrain Mesh or not to be?

I have been eyeballing the USA terrain mesh in the Simviation downloads section for FS2K.
Considering that it is at least 50 pretty big files - that will be a chore downloading and installing, even with broadband.
So, I was wondering - any one here got it? Is it an improvement? Worth the effort, or the big hit to framerates?
Considering that it is at least 50 pretty big files - that will be a chore downloading and installing, even with broadband.
So, I was wondering - any one here got it? Is it an improvement? Worth the effort, or the big hit to framerates?