On the plus side, it's cheap and unlimited. Also, you don't shell for their phones: my friend and his wife picked up used i-phones for essentially nothing.
On the downside, apparently it works by running all the service through the last-generation transmitters (or bandwidth, or however this actually works). So data speeds are not great.
If you don't have a lot of critical data needs (but would like to be able to check e-mail or something once in a while) it sounds like a pretty good deal.
