Title reveals most of my thoughts, but it is definitely a great device with excellent sound quality. The low noise floor makes it easier to hear the minute details in a recording, but the existence of the L30 makes me wonder. Why would you want this over the L30 except if you're already fully converted to the 4.4mm pentacon connecter. The gain function of this devices is basically useless 6dB is nothing that makes anything difference, and the L30 offers both -9dB and + 9dB. Furthermore you can access the full power of the L30 with single ended. Assumed that the L30 equals this device in sound quality, I can't justify buying this unit over the L30 in less the size difference, or the looks offend you of the L30, this unit feels obsolete and I feel stupid for buying it. Also heard mains hum plugged in with the included power brick on one of my IEMS, but no hiss, so it might go away if you have the P50.