I'd stay with the devil you know. this company "Clearwire" is the absolute worst service. you may end up buying equipment that you will not be able to return anfter 30 days. and believe me for the first 30 days you will get good service but after that it will not be the same.
If you have been happy with Sprint's mobile internet, then you will likely be happy with Clearwire's mobile internet, as Sprint is one of their biggest wholesale customers and you are almost certainly already on Clearwire's network.