Kansas City, MO
OK I got the overdrive, I did swap it onto my grandfathered account... it does put a banner next to the plans that says the grandfathered plan will not allow 4G access... which is fine since I don't use this in any areas with 4G-Wimax.
It replaced an old mifi2200 and so far I'm pretty impressed... it seems to be much more capable router than the mifi was... of course it's a much newer device.
It does offer port forwarding and port triggering (the mifi2200 doesn't).
It has 2 antenna ports (3G and 4G-Wimax).
It can be used as a modem directly connected via usb, my mac picked up on it automatically and it connected. I haven't had a chance to try it on windows... but I did try it on my cradlepoint router as a device and it DOES NOT seem to work... will have to mess with that more later.