I have been complaining about the RAM. On my iPad Retina Mini using iOS8, Safari tab refreshes are much better. It almost seems like they suspend each page, because there is a slight delay when accessing the page, but it hasn't refreshed in my limited 30 minutes of usage.
Mavericks Safari and Yosemite Safari is night and day. Much, much better in Yosemite. I wish they would have fixed the problems in Mavericks. Made for a pain in the butt to use with Safari.