Very easy to use, battery life is long (though I've never tested it, I've had rockets sit out on the pad through raffles with the ARTS beeping away and it deployed fine, and then I re-used the same battery for another flight with no problems), and connection to a computer is INCREDIBLY simple. I got a unit when they first came out, and it had a few firmware details that needed to be fixed (fired 0.5 sec after apogee, kinda reminds me of the first-generation R-DAS firmware), but I upgraded the FW myself with directions from Loki and have had NO problems at all. If you've ever used an ALTACC, it's similar but a whole lot easier to use, and Jeff actually *responds* to your emails... awesome customer service.
Great, great unit.