Here is some great information that helped me land on which 3G carrier I want to go with.
http://www.brandsonly.nl/ipad/2011/0...g-and-options/
Also, for Verizon fans that think AT&T is awful, interesting results here.
http://www.pcworld.com/article/18959...ance_test.html
Hope this helps any on trying to figure out which way to go.
Also addresses Tethering.