Installed it last night without issue and it doesn't seem to be any slower. In general I've never had a problem with any of Apple's upgrades.
I couldn't for the life of me figure out how apple released the iphone without copy and paste, so I'm very glad to have it now. The search tool is very helpful as well. Haven't really played with the other features, but I may be one of the few that don't like the landscape keyboard....doesn't feel right to me.
Michael