It's a highly subjective topic and although I don't consider myself an audiophile (personally I think audiophiles are as much a fantasy as 'mobile device power users') and I can only speak for myself regarding the Sennheiser Momentum in ear. I have a pair of them as well as a much cheaper pair of Sennheiser CX 3.00. I use both with my HTC 10's amp & DAC which is among the best right now and to me, the CX 3.00 suits my taste much better, they have a flat response curve and clear high's, mid's and low's which I personally like. The Momentum's are much more user friendly and convenient with in-line controls and straight 3.5 mm jack, the CX 3.00 has none of that, but the Momentum's are too bassy & boomy for my taste and I'm not a fan of bassy, boomy music so they tend to overpower the high's and mid's and and I tend to forsake them. The CX 3.00 does have it's drawbacks though, like that right angled 3.5 mm jack which I find to be more of a nuisance than a feature but in general they're ideal for me. As I said at the start, it's all about personal taste.