There was a short transition time when my iPad 3 seemed a bit slower and occasionally lagged after the iOS 7 update. However it went a way after the first day. Updates often require some background stuff (like indexing spotlight) to be redone, and until it is finished you can have response issues.
Heck, I've seen the same thing on my desktop right after an upgrade. Only it's more obvious since the hard drive kicks in and doesn't stop for a couple hours.
Over all, I've found 7.04 to be fine on the iPad 3. Some people will prefer to turn off the motion affects, but they don't bother me.