ios7 itself is excruciatingly slow on ipad2. noticed in the ui.
I dont mind too much as i will be getting the new mini, and passing off my ipad2 to my parents.
Apps:
the apps my parents use work fine though. these are just some internet tv streaming, web browsing, and some news apps.
The apps that i use (non-gaming) worked perfectly fine and smooth on ios6. But on ios7, those updated apps have slowed to a crawl. I think the developers may have added some different features to those apps to make them do 'more stuff' in the background (some have new features added, not merely a port).
The best i can do is mail the developers and give feedback whenever performance drops too much.