I gave in to temptation and got the HD 650 along with ZMF pads. I might be biased because it's new and shiny but my initial impression is that I like it, it sounds very clean and natural. As expected comfort was poor with the stock pads, but switching to ZMF pads and bending the metal parts of the headband to reduce clamping force was a huge improvement. However it's not quite as comfortable as the Sundara with ZMF Auteur pads as there's less room for my ears to move around with the smaller diameter. I tested it for gaming and it was better than expected, no issues with identifying footstep locations, though the ZMF pads could be helping with that a bit as the review said they improve imaging and soundstage. I don't like the stock cable so I'll have to replace it with something better.