Here I am typing on my iPad 2 . Wish I could take a vid of how the words are dancing about two seconds behind each key press.
Having said that, it's probably twice as fast as it was. That's as good and bad as it sounds, considering some apps (Facebook, Mail) could take a half minute/minute to load. Half of that is on the cusp of my patience, but web browsing is much improved, as it has improved with each update since 7 to 8 , actually (the last iOS 6 update was the worst for browsing, for me.) Not as much freezing, no new issues.
I yanked most of my photos off of it to Free up about 8gb, and updated through iTunes. Might try blowing it all away and restoring. Still not comfortable putting this on the 5s; sad, but my iPhone is one of the few things in my life that works the way I want it to, not going to ruin that.