Not a problem. The first thing I did after buying an ipad was switch to clear.
They offer nation wide 3G coverage yet wont allow you to sign up unless you live in a 4G coverage area.
No loss with your ATT plan,,,, you'll love the 4G and your lucky to be within a 4G hot spot.. Still waiting in Sacramento,,, hopefully by end of this year
Sprint is a part owner in Clear, along with Comcast and some others. They always use Sprint towers around the country.