After extended testing, I have found that the IRIN IN80 was properly functional, the guitar I am using appears to be one of the type that you have to keep the guitar turned up very high, but it did run continuously without auto-shut off. Actually, it ran and ran... literally over 8.5 hours, (at this point it was flashing for a half hour or so indicating low battery), it probably would have ran even longer, but I thought this was a sufficient run-down test, and frankly, 8.5 hours of guitar playing in 2 days is a bit of a chore, and make your loved ones feel abandoned. The really good news is a 1:23 charge time! I look at rechargable devices from a point of view of battery duty-cycle, how long it runs, vs how long it takes to recharge. In this case, it is nearly 7 to 1. So theoretically if you had 2 wireless devices, you could play continuously forever. I don't really have a means of testing range on the device without setting my rig up outside, so the best I can tell you that it remained linked throughout our apartment with no troubles, often through several walls, etc.