I am very satisfied with the sound quality (I used to have Sony in-ears with a lot of boom) and the ANC is also very good (except for vibrations on the bus or pressure waves when fast trains cross each other). My colleague at work has the Bose parts and they are in the same league. In my opinion, the Sennheiser has the slightly better sound and feels a bit more refined and comfortable. I've never made a phone call with the Bose, but the microphone on the Sennheiser is apparently only conditionally suitable for outdoor use.

Compromise? This is a Sennheiser! Compared to the MM-550 (X), excellent especially in terms of battery life, ANR something of the best on the market. Another advantage is the metal headband (the 550's are made of plastic, which breaks with frequent use). The controls take some getting used to (dual-function button is tedious). Minus: more sensitive to overhead lines (600 volts) and in connection with the iPhone often no pairing possible (restart of the smart phone necessary).

I bought the Sennheiser Momentum 2 wireless over-ear. I am very satisfied, the sound is great. Noise cancellation is some of the best, fully convincing. Wearing comfort is also very good. I would buy them again!