The Sprint U301 is the best USB modem for Sprint subscribers right now. It bridges Sprint's 3G EVDO network and Clearwire's new WiMAX network and delivers better 3G performance than the earlier U300 model. I'm disappointed in the speeds we've been seeing from WiMAX in general, but that's not the U301's fault.

The U301 is a pretty big USB modem at 3.5 by 1.3 by .92 inches (HWD) and 1.3 ounces, but its black body looks more professional than the U300's gray. The U301 has an unusual "halo" antenna that wraps around the top of the device, a port for an external antenna, and a flip-out, hide-away USB jack to connect to Macs and PCs. A single LED shows different colors depending on whether you have 3G, 4G, or no signal. Plugged in, the U301 runs much cooler than the U300 does.

Like the U300, the U301 requires Sprint's SmartView software, which I have mixed feelings about. Provided by Smith Micro, the little connectivity panel is unobtrusive and lets you easily switch between 3G and 4G modes. But it can take a while to load and recognize your modem.

Sprint's new WiMAX network, operated by Clearwire, is slowly spreading across the country. Major WiMAX cities right now include Philadelphia, Honolulu, Las Vegas, Seattle, Atlanta, Dallas, and Chicago. Boston, Houston, New York, San Francisco, and Washington D.C. are all coming sometime this year, according to Sprint. Outside of WiMAX regions, the U301 falls back to Sprint's nationwide EVDO Rev A 3G network.

I tested the U301 on WiMAX in Philadelphia, PA and on 3G in New York City. I've previously used other WiMAX devices in Las Vegas, NV. and Baltimore, MD. WiMAX promises speeds of 3-6 megabits down, with bursts of up to 10 megabits. But that seems to only happen under ideal network conditions—and Clearwire's buildout is so poor that you're rarely in ideal network conditions.

In Las Vegas, for example, many of the major Strip hotels aren't covered by WiMAX, and coverage within buildings in general was weak. In Philadelphia, sometimes the network didn't even work outdoors. My WiMAX modems dropped to 3G in a window seat at northeast Philly's Mayfair Diner and while waiting for a train at the city's elevated Frankford Terminal. That's just unacceptable.

The U301 uses the Qualcomm QSC6085 3G chipset and the Beceem 250 WiMAX chipset. The U301's WiMAX performance ran neck and neck with the earlier U300, though both USB modems performed far better than Sprint's Overdrive WiMAX-to-Wi-Fi router. I got an average download speed of 2.25 megabits/sec with the U301, with peaks of 5.04 megabits. Yes, that's faster than 3G. But it's much slower than what Sprint promises.

It's also, sometimes, slower than amped-up 3G. When I tested the WiMAX modems against a T-Mobile WebConnect on T-Mobile's new HSPA+ network, the 3G modem sometimes provided faster download and upload speeds than the U301, and it was often faster than the Overdrive. Of course, HSPA+ right now only exists in northeast Philadelphia, but this shows that WiMAX may soon be outpaced by faster technologies. WiMAX upload speeds with the U301 averaged 708 kilobits/sec, with a peak of 1 megabit. The U301 was faster than both the U300 and the Overdrive on uploads.

Connected to 3G, the U301 outpaced the competition on consistent download speeds, with an average speed of 1.1 megabits/sec and a peak of 1.47 megabits. The U300 and Overdrive both peaked higher, but delivered lower speeds across my test sample. The U301 had an average upload speed of 322 kilobits/sec on 3G, also faster than the two competitors I tested.

In seven rounds of testing, the U301 showed the strongest 3G and WiMAX signal strength five times, when compared to the U300 and Overdrive.

There's no reason to buy a 3G-only modem from Sprint any more, so if you're shopping for a connection, it's really a choice between this and the Overdrive. The Overdrive is much easier to use, and lets you connect five devices to the Internet. But if you only want to connect one laptop at a time, the U301 is your best bet for speed, reliability, and connection quality. It's our new Editor's Choice for Sprint modems.