Do you use an Android handset on a prepaid plan? I want your opinion.

Sprint Speed just doesn't cut it anymore. I'm getting 1990's style 56K speeds in 2012 which is ridiculous! I am currently using a Sprint Galaxy Nexus, which I love. I've looked at T-Mobile's Monthly 4G plans and Simple Mobile, but want to know more from people who have actually used them. I know Simple Mobile has an AT&T and T-Mobile component, so be sure to let me know which network you're using. If you're using something other than what's listed, sound off on those too! Make sure to list the device you're using as I am leaning towards buying a GNex from the Play Store but who knows? I may choose something else. Thanks fellow denizens of Android Army!