Pros: seductive vocals, overall SQ, relaxing signature combined with a good speed
Cons: soundstage is not large enough, clamping force is incomfotable for big heads
There are some who say HD650 demands for expensive amps. I disagree, HD650 is great with lesser sources/amps and excellent with higher gear. From Hi-Fi cans I tried (DT990, DT880, HD600, AD2000, AD1000PRM, W5000, D2000, K701), HD650 is less finicky to pair, while it is on top of this heap in terms of SQ. It is also moderatley priced for Hi-Fi can, half of those mentioned above are more expensive. Add that I bought mine barely used for $150, so it is a keeper for me.
Soundstage becomes bigger with better amps, like WooAudio 3 with upgraded tubes. Clamping force can be reduced, if you store HD650 with some spreader for headband. I recommend not to store it on a things like basketball, since you will flatten the earpads.