I like the nad HP 70 design better than the PSB m4u 8, however the Nad has a internal battery that isn't user replaceable, the PSB m4u 8, does that's important to me as you can just use normal AAs batteries if and when needed when traveling, being sister companies they both should sound quite similar I take it, I currently have the B &W P7 wireless I enjoy them they sound quite good to be honest a tad bass heavy, and use them with my pixel 2 xl Daily traveling to and from work, I also have the PSB m4u 2, and the Nad HP 50, and I enjoy them a tad bit more than the B&Ws, especially yhe m4u2s maybe it's the room feel tech in Paul Bartons headphones that makes a difference, i don't know, looking forward listening to both and comparing to my old cans