They are active, which means you need AC power. In many venues that can lead to ground loop hum. I much prefer passive transformer DIs - no power, and isolates ground loop hum from other AC toys you might be using.
ART has some inexpensive passive DIs that are just fine. ART stuff is typically built really tough. I haven't compared to the Behringer, but as Kiwi writes above, go passive. my inclination would be to stay away from cheap active DIs.
I have a DI800. It's active, but it can be powered by phantom power from the desk. It's also got ground lifts for each channel (very handy) pads for each channel (very handy) and a gain boost switch for each channel (pretty unusable, very noisy).
Overall, it sounds just the same to me as other active DI's and I've had no problem with it.
I've had it for 2-3 years and use it live regularly.
compared to other 8ch systems, it is insanely cheap (and I need 8 channels live with my industrial/electronica/metal rig)