Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
I found mine was for a few days, until apps started loading up. Now it's a bit bogged down. But no worse from previous iOS versions.
 
This should be sticky-ed as "Always update to the latest software for the best experience" to prevent the dozens of questions about this and that and "why i wont upgrade"
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.