The clamp isn't bad. I wear them all day at work without issue. They can be bent a little too if it is too much. I have a bigish head for a reference point.....How's the clamping force? That was one of the things I hated with the Senn M4, couldn't wear it for more than 30 minutes. Sound was decent but if you can't keep it on your head, what's the sense? How's the sound with the Panda?
The sound out of the box is on the warm side. I can't seem to find a huge hole in the spectrum. Bass wise they are really good. Nothing compared to my TH-909s. They come with the option to flash a firmware that installs Sonarworks SoundID compatibility. This allows you to set an EQ preference and save it to the headphones. Kinda cool. I bass boosted them and they are to my liking.
https://www.sonarworks.com/soundid