I just acquired a pair of N3's. They remind me a bit of the Sennheiser Momentum, with more sparkle to them.
They sound very natural to me from the first moment, usually, with new gear, I immediatly find something out of place compared to what I'm used to, not with these, which is a good thing.
I read someone comparing them to HD650, I wouldn't go as far. But Momentum level, for sure.
They sound lovely, lush, laid back out of my Walkman A35. Out of a Cayin N3 they gain weight and punch, but also more sparkle, which is something I'm not all pleased. But there is more definition also.
I also tried a Shure over the ear cable I had lying around, I think I prefer that over the ear configuration better, Shure cable seems sturdier too.