Editor's Note: After this review was completed, Sprint released a firmware update which they said improves WiMAX signal reception (and therefore also speeds) on the Overdrive. We will re-test the device next month.

The new Overdrive, from Sierra Wireless, can connect any Wi-Fi device to Sprint's 3G and WiMAX networks. Ideally, this means that anything you own with Wi-Fi will now connect to the Internet anywhere—whether it's an iPod touch, a digital camera Eye-Fi card, or a netbook. The Overdrive can also share connections and files among five users at a time. But WiMAX's weak coverage and speeds mean you often get less than Sprint promises.

The Overdrive is a sleek, comfortable little black brick. It's much thicker than a Novatel MiFi, but it gives you both WiMax and 3G while the MiFi is 3G-only. The device has a power button, a mute switch, a microSD port for charging, and a microUSB memory card slot. If you stick a microSD card in, it becomes a shared drive for PCs and Macs hooked up to the router. That's quite neat.

The LCD display on the front of the router is also nice. It tells you the device's SSID, password, signal strength, whether GPS is enabled, the number of devices attached to the router, the time connected, and the data transferred.

Since this is a Wi-Fi router, you don't need any drivers for it. But if you want to connect the Overdrive to a Windows PC as a USB modem, you can do that too. When I connected the Overdrive to a Windows 7 laptop with a micro-USB cable, it automatically installed its own drivers and connected as an NDIS link using Windows' built-in software—smooth and easy, without any clumsy connection apps. The Overdrive has a good-looking management console, accessible by sending a connected PC to http://192.168.0.1. From the console you can monitor signal strength and battery life, check out who's connected to the router, and control a wide range of router settings—yes, this is a decent Wi-Fi router.

Within the router settings are the ability to change the screen backlight, set your 3G, WiMAX, and Wi-Fi options, and enable port forwarding, port triggering, UPnP, a DMZ, and static IP addresses. There's none of the parental control-type options you see on some other routers, but there's enough flexibility to set up the router for gaming. (If you're a gamer, though, watch out: I got average pings of 104 ms in my WiMAX tests, which is one heck of a lag.) Sprint's new WiMAX network, operated by Clearwire, is slowly but steadily 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.

But the Overdrive delivered lackluster signal strength and speeds compared to the dedicated Franklin U301 modem I was testing it against—and it was often even slower than a T-Mobile WebConnect stick hooked up to T-Mobile's new "3G+" HSPA+ network. In seven tests, the Overdrive got slightly better signal than the U301 twice, but the U301 bested it five times. And the Overdrive's WiMAX download speeds were just sad, averaging 700 kilobits/sec and topping out at 1.65 megabits/sec. That's much slower than the 2.25 megabit average I saw on the U301 in the same locations, at the same times. And considering that Sprint promises 3-6 megabit downloads, the Overdrive just wasn't delivering. Sprint says a firmware update that's now available should improve reception and speeds.

Upload speeds on WiMAX weren't much better, averaging 391 kilobits/sec and topping out at 950. That just feels so … 3G. The U301 fared better, averaging 708 kilobits/sec—but the T-Mobile 3G stick did best, with 798 kilobits/sec downloads.

On 3G, the Overdrive still lagged the U301, but not as badly. Download speeds averaged 954 kilobits/sec and topped out at 2.02 megabits/sec (faster than WiMAX) while upload speeds averaged 280 kilobits/sec and topped out at 514. The U301 provided even better speeds, averaging 1.1 megabit down and 322 kilobits up, but the Overdrive's performance wasn't bad.

The Overdrive's 1800 mAh battery lasted between two and three hours in various tests, but it can charge off a laptop if you're in a pinch.

The fact that I saw faster speeds on Sprint's 3G than on WiMAX speaks to Clearwire's awful buildout of WiMAX pretty much everywhere I've been. Sprint better be collecting some money from their erstwhile spinoff/partner, because this network just isn't up to snuff.

I'm convinced this isn't primarily the Overdrive's problem. I tried the Overdrive in both Las Vegas and Philadelphia, and I've tried other WiMAX devices in Baltimore. In all three cities, I got spotty coverage where Clearwire's map told me it was strong. The Las Vegas network didn't work in major casino hotels, even right by a window. In Philadelphia, the Overdrive dropped to 3G at a diner and a train station in the northeast part of town.

The Overdrive competes against single-PC modems like the Franklin U301 and also against Novatel's MiFi, a super-slim 3G router. If you want to connect iPods, iPads, and such to the Internet using Sprint's network, this is a good way to do it; we can only hope the WiMAX network will get better, and MiFi devices will never be equipped to use WiMAX. But for the road warrior looking for the best possible connection, I'd still go with the U301 modem, our current Editors' Choice.