SP1 over demo mode performance.

Hi,I have not activate my new install (+SP1) yet. So, it is running in demo mode. I am keeping a copy of the pre-patch FSX on my drive, and I just renamed it to a different directory. Since I am seeing all those posts of great SP1 performance, my question is, do I get the same great performance running in demo mode? The reason is while I am see performance increase in texture load time, I am not see much increase in fps (JFK) with traffic at 85 percent. However, I do notice when I pause the game, fps goes up by 80% where as with the unpatched version, it only goes up about 50%. Another question is. If I activate the new install, what happens to my previous installation? Thnx.