I've got these as a part of the Yamaha E353 deluxe package and I have used them with the Yamaha.
Pros: The sound is excellent, very clear. The ends turn 90 degrees, hence finding a position which is comfy will be easy. I'm using them mostly on the keyboard as piano and the lows are clear enough.
Cons: They sit somehow artificial on the ears and they have the '90s feeling. This will not be an issue, as the sound is great and the ends are soft, but might have this feeling.
They arrive with the 6.3 adapter which is welcomed as these can be used on a keyboard or on any other device (smartphones, etc..)
I would recommend them for amateur use for someone who wishes to have few headphones pairs around the place at a low budget range.
I would not recommend them for professional use as I never had professional headphones before to compare, but they might be fine. Probably another member will be able to provide this comparison.