Got my 500s about 2 weeks ago. Been breaking them in but out of the box was spectacular sound anyway. W sound sig is probably my favorite. Plugged into a player these phones power real nice with a sturdy solid low end, slightly recessed mid range with a nice boost in the upper mids which is great for female vocals, and highs that are dynamic, clean and natural. The phones are rather on the warm side overall but are really detailed. Lots of energy and lots fun. Whither its opeth, or carcass, or bad religion or ayumi hamasaki or Alice deejay these HP's handle everything really well.
The only thing soundwise that I'm personally not crazy about is how the sound changes significantly depending on dap or amp used. My cayin c5 really pushes the low end on these headphones really hard. Even with boost off the 500s just want to thump making it a EDM, hip-hop, pop type of modern sound headphone to me. Cayin is a warm bassy amp so probably just need a cold clinical sounding amp to tame the beast. Aside from that I'mhappy just going straight into a dap. Less bulk and easier portability that way.
Speaking of portability. I'm not sure these headphones are portable even though they fold up. These things are silly big. Silly heavy too. The aluminum earcups really weigh these down. That said, comfortability for me is fine. Clamping pressure out of the box is a smidgy bit tight but stretching and working em out helped almost immediately. Ear pads are hard so really until they soften up they are not comfortable at all. Luckily for me though they fit my head out of the box. With no adjustment they just fit. My head/cap size is 7 1/4 round with a round to slightly egghead shape. Wearing a ballcap under the phones really helps a lot. Also while the ear cups are small in circumference, my smedium sized ears fit completely inside. Probably why these are not so uncomfortable for me. They are not comfy,but they are not uncomfy.
Be back with more thoughts later.