Picked up a pair of Sony MDR EX650AP out of curiosity - interesting pair of earphones a little bit different to run of the mill stuff with a few positives and negatives.
Has the typical "high-res" sound of the MDR line, crisp detailed sound and impressive ability to sound like listening to much bigger drivers positioned further from your ears. Like the MDR line in general though there is a clinical feel to the sound, though expansive there is no richness to it, no warmth or organic smoothness. The bass has impressive amount of "slam" to it by almost any headphone standard but lacks for deep low bass - none of the menacing rumble like the Sennheiser Momentums. Treble sometimes is uncontrolled - piercing/screechy. In some specific circumstances I think the brass enclosure and lack of flex worked against them with the occasional moment where they sounded coloured and slightly off articulation but it was fairly rare.
Surprisingly comfortable and sit securely for prolonged use though I still notice they are there - I prefer earbuds over this style.
Overall quite like them, but there are other options in the MDR line which do the same thing better so I'd only choose them over those for portability/comfort reasons, but like with some of the other headphones in my collection great as a novelty but if I had to choose one headphone to use always it wouldn't be them.
Being super sensitive they also produce hiss quite badly on any hardware which isn't ultra-low noise.
EDIT: Haven't tried them for gaming yet - I generally find these kind of earphones or closed back headphones tend to perform poorly for my tastes compared to open back or the Sennheiser MX line.
EDIT2: Also very unforgiving with mp3s, etc. - even fairly high bit rate - cymbals and similar instruments in some tunes turn into high pitched "smish, smish, smish" sounds with them which isn't exhibited to the same degree with a higher quality/lossless version of the same tune though those kind of instruments tend to be a bit piercing with these earphones.
EDIT3: After using them for a bit I think I will have to build a little attenuator circuit for them for more general use - aside from ultra-low power output or devices with ultra-low noise levels they hiss far too much and the treble just destroys the listening experience in too many cases for anything which isn't a lossless recording of perfectly mastered audio as any little high end compression artefact gets reproduced as a piercing smush.