Sierra Wireless 313U (USBConnect Momentum) for AT&T - Refurbished, Like New
[K-ATT-MOMENTUM]

This is now a fairly old piece of equipment, but it works fairly well. With my AT&T Unite Pro (Netgear 781S) attached directly via USB, I can get up to 75Mbps down. But with this 313U, I top out around 35Mbps because it lacks some of the newer features bonding additional channels to increase throughput. That said, it's very straightforward and easy to use and much more widely compatible with various 4G routers than the newer 781S. Plus, this is just a modem, compared to hotspots like the 781S that are their own integrated router/firewall, and you have no way of truly disabling or bypassing it.

The AT&T communication management software for Windows that it forces you to use is probably fine for your average user. But for power users who don't want or need its features and restrictions, just want it to work directly, I recommend upgrading to the AT&T Global firmware 3.05.10.02. It's available at http://mofinetwork.com/firmware/stick_updates/313u_ATT_Global_Firmware_03.05.10.02.zip