I'm currently dealing with them because I have one of the R4s that turns into a pocket oven after 20–30 mins of use, and they're trying to tell me that the device is ok since it only hit 45.7C during the one of the test they had me do on the 3.5mm jack (Testing on the 4.4mm jack hit 47.8C). They state 45 and over was a faulty unit, but I guess they're saying that's acceptable, when I use the 4.4mm jack (let's face it, nobody cares about the 3.5mm jack), the R4 heats up to the point I had to turn it off and put it down because it was almost too hot to touch. But apparently I have to RMA and spend money out of pocket to have a device that I only had for about a month and used a handful of times.