Enjoy it while you can! I've been hoping to do this, too, and thought I might get a chance with CN/Red Pocket.
I'm also trying to enjoy my FreedomPop Global SIM while I still can-- most users seem to report now that these will only connect to T-Mobile 3G (no more AT&T). It's already killed the devices (for practical purposes) in those areas where T-Mo has already re-purposed frequencies from 3G to LTE. Mine will only connect to T-Mo as well-- but we still have T-Mo 3G here.
I've ead a couple of threads elsewhere about the Global SIM not connecting to AT&T anymore. I tested mine using Signal Check Lite, and can confirm that it will only connect to T-Mo: the phone still sees the AT&T tower, but will not connect with data even if I manually select the AT&T signal. SpeedTest showed 3.5 and 6 mbps on 2 different tests (down), so I've lost coverage, but not throughput when I have coverage.