I had BAD wifi problems initially. This despite my Palm Pre connecting with no problems to wireless feeds all over. Apple recommends that dual-band routers have their different bands set up as different wireless networks. At home I have a dual b and g band router, but I never use the b (my only devices are either g or n band). So I just turned off the b band and made my router g only. This produced a DRAMATIC improvement, but I still had problems with hesitation (on other networks, as well as my own). I was still unhappy, both because of the remaining problems, and because I intend to use my iPad with strange wifi networks when I travel, and I'm not going to be able to ask my hosts to change their browser settings for my convenience!
I got an appointment at the Apple store, and the "Genius" offered to switch out my iPad within fifteen minutes. That was just a couple of days ago, no problems since. (knock on wood)