in snow leopard there was a option to increase the speed. i had it increased to the fastest speed. and now there isn't an option .. which makes it slow according to what I'm used to.
you know what, i just looked at the activity monitor and it said safari was using over 4 gigs. The process was called something like "Safari Content". I killed the process and I'm now typing this posts with no interruptions. The last post safari was constantly interrupting my typing with pauses. The scrolling is more responsive too.
One thing I'm still noticing though is that if i load a webpage, and try to scroll while its finishing loading the page (even though content is mostly already displayed on the page) the scrolling will stutter, jump, freeze or jitter.
my internet connection is pretty good to. I can download an iTunes movie in probably twenty minutes or more.
the scrolling seems to be affected by safari loading the webpage. So safari is taking longer to load pages, or safaris taking the same time but now it won't scroll smoothly until the loading (URL bar) is completely finished.
I have the new MacBook Air 13" running the dual-core i5s and I'm finding that for certain applications (safari, the app store, and a couple more) scrolling is not completely smooth. I tried to eliminate the "Safari web content" process and that only made the problem worse. It seems to be an issue on more busy websites: tumblr, Facebook. However, after letting the website load completely its still really jittery. This forum thread, however, is completely smooth.