Yes, iPad2. I have just downloaded 8.0.2 and early indications are good. Not so scratchy or fragile any more.
FB is probably one of the most popular apps I should think so, yes, why not test that one before release?
8.0.2 is a step forward on my iPad 2, but there are still problems. Composing a post will sometimes hang Safari. The Facebook app crashes all the time. The 3G connection seems to disappear after a while, requiring a restart before it shows up again.