Wireless data hotspots are quickly becoming all the rage among travelers and geeks who don't like to be tied down to their homes and coffee shops. Though 3G USB sticks have been growing in popularity for years, the new WiFi hotspot-type units are picking up steam because they allow users to share their wireless data connections among multiple devices or a group of friends, so long as everyone has WiFi.

Two of the most popular ones in the US right now are the Novatel MiFi from Verizon and the Overdrive 4G from Sprint. We managed to get our hands on both to give them a test run, and it turns out that deciding which is better wasn't quite as easy as we expected.

The hardware

The MiFi is significantly thinner than the Overdrive

The Overdrive 4G is a 3.1" square that is 0.6" thick and weighs 3.5oz. It's made by Sierra Wireless and connects to both Sprint's 3G and 4G (WiMAX) networks, where available. The device comes with a micro SD slot (bonus card reader, I guess?) and allows up to five simultaneous WiFi connections.

The MiFi 2200 is made by Novatel, sits at 3.5" by 2.3" by 0.4" thick, and weighs 2.2oz. Sprint sells one too, but the most well-known is sold by Verizon for use with its 3G network (the one we tested connected to Verizon as well).

Both devices can work independently without ever having to connect to a computer, but they also work as tethered modems via USB.

The MiFi has aesthetic superiority compared to the Overdrive—no question about it. The MiFi is credit card-shaped, thin, and easy to slip into a pocket (pants or otherwise), while the Overdrive is fat, bulky, and utilizes a slightly cheaper-looking plastic for its casing.

Setup

On top of the MiFi's pretty looks, it also performs better at basic tasks like turning on and shutting down. While the MiFi can power on and off and be ready to use within seconds, the Overdrive takes its time powering on—taking a minute or more. If that sounds bad, things are about to get worse. Powering down can be comically slow, taking several minutes on its better days, and hanging indefinitely on its worse ones. There was one point at which we left the Overdrive trying to power down for 90 minutes before we gave up and removed the battery, and that wasn't the only time such a thing happened.

Aside from these issues though, the two devices work very similarly. You don't need to set them up on a computer in order to start using them if you don't want to—you can pop them out of the box and turn them on (give or take an extra coffee break for the Overdrive), and connect via the network name and password displayed on the device. On the MiFi, this is located on a sticker on the bottom, while on the Overdrive, it's displayed on the built-in LCD screen.

If you want to customize the SSID and passwords for your access points, however, you can—or at least, you're supposed to be able to. With the MiFi, they tell you to connect it via USB to change the settings, but on the MiFi unit that we tested out, we were unable to bring up the right files on any computer we connected it to. This isn't the only way to do it, though. There's also an admin interface that you can access by going to http://192.168.1.1 in the browser when connected to the unit—from here, you can change the settings.

The latter goes for the Overdrive as well—just connect via WiFi and go to http://overdrive/ in your browser, which will load the admin interface. Once you enter the default admin password that comes with the unit, you can change the SSID and password to whatever you like.

Speeds

So, the Sierra Wireless hardware sucks while the Novatel hardware is slick. However, there's one area where the Overdrive has an obvious advantage: its ability to connect to a 4G/WiMAX network.

Sprint's 4G coverage is spotty at best, especially if you travel a lot (and since this device is targeted towards travelers, we assume you probably do). There are pockets in some major cities, and we're lucky to have pretty decent Sprint 4G coverage here in Chicago where we did our testing. However, this is clearly a major selling point for the device, so if you don't live anywhere near a city that might get 4G coverage in the next few years, the Overdrive's appeal is obviously diminished. (The Overdrive can connect to Sprint's much more widespread 3G network, though, so not all is lost. It just becomes an average data connection, at that point.)

With that said, we tested the MiFi on Verizon's 3G network, the Overdrive on Sprint's 4G network, the Overdrive on Sprint's 3G network, and just for an extra network speed comparison, we threw in the iPhone 4 on AT&T 3G. Before we get to the data, the first and foremost lesson is that data speeds can be random and unpredictable. They can vary heavily throughout different parts of the day, different parts of a building, and which towers you're on, even within the same city. So take all of our numbers with a grain of salt—they are really meant to show a general comparison and don't necessarily represent exact numbers of what a particular user will get all the time.