Unlike the hotspots from AT&T, Sprint, and Verizon, T-Mobile's works with 802.11b/g only; it can't use the newer and potentially faster 802.11n protocol for Wi-Fi. The router can service up to five clients, but it lacks the GPS location abilities that the other three hotspots have.
On the other hand, the T-Mobile hotspot can do something the others can't: It has a connector to plug in an external antenna to boost a weak signal. The antenna is available from third-party sellers for $50.
Like the AT&T and Sprint hotspots, the MF61 has a handy MicroSDHC card slot that lets connected users share data. It works with cards that hold up to 32GB of data. The hotspot supports Windows and Mac OS X computers.
I was able to connect to the MF61 hotspot on the first try. Once online, I was able to change the network's name and encryption settings, update its software, and change its security settings; it can handle all the recent encryption protocols including Wi-Fi Protected Access 2 (WPA2). Like Sprint's MiFi 4082, it has a Wi-Fi Protected Setup (WPS) button to make connecting clients a snap.
To extend its battery life, the T-Mobile hotspot goes into sleep mode after 10 minutes of inactivity. However, unlike the hotspots from AT&T, Sprint, and Verizon, the MF61 doesn't let you adjust when it goes to sleep.
In my tests, the MF61's 1,500 mAh battery pack ran for 4 hours and 49 minutes on a charge, 43 minutes longer than Sprint's MiFi 4082 and more than an hour longer than Verizon's Samsung SCH-LC11.
Able to keep a client online 120 feet away, T-Mobile's MF61 has the longest Wi-Fi range of any hotspot I've seen, besting the Verizon hotspot's range by 25 feet.
In my data throughput tests using T-Mobile's HSPA+ 21 network, the MF61 hotspot had mixed results. Over the course of two weeks of heavy use at several locations on the East Coast, the MF61 averaged a respectable download speed of 3.26Mbps, peaking at 7.61Mbps.
I can't definitively say how that stacks up to the other hotspots and networks I tested because I didn't test T-Mobile's system at the same times that I did the others. Unscientifically, however, the T-Mobile hotspot came in well behind Verizon's 11.3Mbps average download speed and slightly ahead of Sprint's 2.33Mbps and AT&T's 1.65Mbps.
T-Mobile also came in second in upload speed with an average of 1.23Mbps, behind Verizon's 3.30Mbps and ahead of AT&T's 630Kbps and Sprint's 360Kbps.
The T-Mobile hotspot's latency came in at 222ms for a third-place finish behind Verizon's 76ms and Sprint's 157ms but ahead of AT&T's slow 334ms. High latency translates into fairly long waits for the network to respond to requests.
T-Mobile offers a dizzying array of service plans with an option for occasional travelers or those scared of commitments. With a two-year contract, online discount and mail-in rebate, the hotspot costs $80; there are four monthly service plans that provide 10GB ($85), 5GB ($50), 2GB ($40), or 200MB ($30) of data. (See our data plans and pricing table for how these plans compare to the competition.)