T-Mobile Sonic 4G Mobile HotSpot Review

The T-Mobile Sonic 4G Mobile Hotspot taps into the carrier's HSPA+ 42 network, promising average download speeds of 10 Mbps. This sleek device can connect up to five devices simultaneously and sports a sleek design. It also comes with an SD card slot for sharing files among multiple gadgets and a helpful OLED screen that shows info such as signal strength and battery level. Read on to find out how this hotspot stacks up to the competition.

Design

The Sonic 4G is the most fashionable hotspot we've tested. It has a dark, smooth reflective face--it could easily double as a pocket mirror--with curved edges that cascade into glossy black side panels and a rubberized back. At 4 x 2.2 x 0.6 inches and 3.9 ounces, it's about the same size as Verizon's MiFi 4510L and the AT&T Elevate, but it looks more like an oblong stone than a rectangular hotspot. The power button sits on the right side with a WPS button just above it. On the bottom edge is the sole microUSB port.

Turning on the device illuminates an OLED screen with indicators for signal, battery, and number of users connected. In addition to the SIM card slot under the back, there's a slot for a 32GB microSD card, which turns the Sonic 4G into a storage- and file-sharing hub for connected devices. File sharing is enabled by going to http://mobile.hotspot, entering the administrator password, and changing the web sharing settings under the microSD tab. Once connected, we were able to upload or download files as needed.

The Sonic 4G is able to connect to up to five devices at once. Like the AT&T Elevate 4G and the Sprint Overdrive Pro, it also supports a tethered Internet connection via USB.

Coverage

T-Mobile touts that it has America's largest 4G network, covering 191 markets and over 200 million people in the U.S. The carrier's fastest HSPA+ 42 technology is available in more than 150 markets.

Performance

While testing in the Lincoln Park and Mayfair neighborhoods of Chicago and near-west suburban Oak Park, the Sonic 4G mostly held its own, but its speeds were wildly inconsistent. On our 10 Speedtest.net tests in for each of the three locations, we found that both the download and upload speeds varied greatly from minute to minute. We saw download speeds as fast as 15.43 Mbps but as slow as 1.74 Mbps at the same location within a few minutes. Despite this, the Sonic 4G's Speedtest.net download average of 7.51 Mbps was 2 Mbps faster than the Sprint Overdrive Pro and 1 Mbps faster than the AT&T Elevate. The Verizon MiFi 4510L blew all of them away with an average of 23.5 Mbps.

On the upload portion of Speedtest.net, the Sonic 4G averaged 1.26 Mbps, slightly faster than the Overdrive Pro (1.18 Mbps), but way below the 3.34 Mbps average of the Elevate 4G and the 4.7 Mbps speed of the Verizon MiFi 4510L.

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Downloading and Uploading Large Files

Downloading a 151MB OpenOffice file on the Sonic was also less than speedy. It completed the task in an average of 151 seconds, 10 seconds slower than its closest competitor, the Overdrive Pro. The MiFi 4510L was once again the fastest, as it downloaded the same file in 81 seconds.

Uploading a 6.5MB file took an average of 60 seconds, though the Sonic 4G was only 2 seconds slower than the Elevate 4G. The Overdrive Pro completed the task in 41 seconds, while the MiFi 4510L smoked all of them by completing it in an average of 14 seconds.

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Web Surfing

We then calculated the average time it took to load Laptopmag.com, CNN.com, ESPN.com, and NYTimes.com. The Sonic 4G wasn't slow, but it certainly wasn't fast. The Sonic 4G took an average of 12.1 seconds to load a site, a full 4 seconds behind the Overdrive Pro (7.9 seconds) and almost twice as slow as the MiFi 4510L (6.8 seconds).

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Battery Life

The Sonic 4G is rated for 4.5 hours of continuous use and 150 hours in standby. We used it several times over a few days and the battery only decreased by one bar.

Data Plans and Value

T-Mobile currently sells the Sonic 4G for $99 with a two-year commitment and a choice of three plans: 2GB for $40 a month, 5GB for $50, or 10GB for $80. While users won't incur overage fees should they go over the data cap, the speeds will be throttled after using up the monthly allotment.

Verdict

While we like the design of the $99 Sonic 4G and T-Mobile's overage-free service, the inconsistent data speeds are a problem. When this hotspot is fast, it's very fast. When it's slow, it's workable, but not knowing which type of speed you're going to get is frustrating. We suggest going with the Verizon MiFi 4510L, which is both faster and less expensive up front.