Having checked Sprint's coverage maps and seeing that both 3G and 4G was "available" at both locations, I ordered the $78 Overdrive Pro. A few days later the unit arrived and it took me an hour or so to get it configured correctly and signed up for the data plan. My home is in the middle of a 4G dead zone so I could not verify that access but the 3G seemed to work okay. The first real-world use was the next day on a CalTrain ride up to San Francisco, a trip that my wife and I had scheduled a week before. I brought along my 4th generation Touch. I got good access on the 4G system most of the way. When that dropped off, the unit switched to 3G but I was still connected. In SF we walked from the train station up the Embarcadero to Pier 17, a distance of about 2 miles. I wasn't monitoring the Overdrive Pro all of the way, but whenever I checked my iPod, I had network access.
I've used the unit for the past week here at work. I'm getting a 10-20% 3G signal in my cubicle (about 20' from the windows). 4G coverage is non-existent at my desk. But in a workroom/lab further inside the building, I do get a steady, but weak, 4G signal. It's good enough to stream a radio station feed, something I wouldn't normally do with 3G as it would eat into my data allotment. I'm guessing that the Sprint cell tower is located on the opposite side of the building from my cube. Outside it's great. I realized the other day that I could probably FaceTime with the members of my family while driving in my car
The unit itself is about 3" x 3" x 0.5". There's a power button below the small LCD. Press and hold to turn it on and off. When on, two quick presses brings up the first of six status screens (keeping double-pressing to cycle through the remaining menus). The main screen shows the signal strength, whether you're connected to the 3G or 4G system, the number of WiFi devices currently connected and the battery usage. Other screens will show the WiFi settings, if there are any alerts to deal with, the amount of 3G and 4G data that's been transmitted, the overall network status and if there's any software updates available. The battery seems to last about 6 hours of intermittent use. It does get a little warm when powered via the AC adapter, connecting to a MicroUSB socket. There's also two antenna jacks next to the USB port. My understanding is that you could mount the unit into a desk docking station and that it provided a slight boost to the WiMax signal. It's also my understanding that it didn't work very well as Sprint quickly withdrew that peripheral.
Sprint's 4G WiMax network is basically an obsolete system. As is typical for cell phone broadcast technology, it might only be around for a few more years before it (and LTE) gets replaced with something else. If that's the case, then I don't need to worry about any contract and I'll deal with that bridge when (if) it comes. It's also my understanding that since I signed up for the $35 plan, I'll be grandfathered in when this plan is withdrawn next week.
ref: http://www.virginmobileusa.com/marketin ... o-old.html ($5/$35/$55 unlimited 4G plans only available until Oct 31, 2013)
ref: http://www.virginmobileusa.com/mobile-b ... /overview/ ($5/$25/$55 plans w/o unlimited 4G)
ref: http://www.virginmobileusa.com/mobile-b ... 2-go/faqs/
EDIT (Jan 5, 2015): A few months ago Sprint announced that it will be shutting down their WiMAX service by November 2015. It's unknown at this time what, if any, plans are there to migrate to LTE when this happens. I guess the worst case is that the 3G will still work and I simply won't have access to a 4G (WiMAX) signal (and unlimited data) any more.
ref: http://www.usatoday.com/story/tech/colu ... /19917605/
ref: http://www.engadget.com/2014/10/09/spri ... er-6-2015/








