I had the M300SE a few times and didn't notice the popping. There was an update to the firmware and all the new ones should have it, probably fixed it. The 4.4mm balanced out is pretty good, the 3.5mm is limited though. The hardest to drive headphones I could get good volume is the Hifiman HE5xx and it sounded really good. The DL200 I have now is substantially better on the headphone amp, but it takes up a lot of desk space. Hook that up to a Sabaj A20h and you have an excellent setup for more power down the road if needed on a low budget. The black M300SE really looks cool with it.