The 4G is hit and miss, honestly I don't know if the 14 days is enough. I occasionally get a few decent weeks out of it, but then it goes flaky and trust me 2 days of flaky totally offsets 2 weeks of decent working as you will end up constantly messing with it to maintain a connection.
That said the prices are the same between plans so maybe taking the plunge knowing you may be locking your device to 3G to actually maintain connection is not a big deal. The other issue though is their current devices seem very flaky right now also, so personally I would advise waiting a bit longer or going with some other 4G carrier.
