i found open and closed back to ve so different in feel, that even with similar tonality you still have very different sound. also the dt990 pro is a bit flawed, while the hd599 does what it wants to achieve pretty good.

the sony on the other hand is an apples to oranges type of situation

They don't. I use them when I don't want or just can't use my proper Headphones. You know, outside my flat or when I'm at work or cooking and don't want to bring around my DAC into my kitchen

Incomparable. You’re talking about a closed back wireless ANC headphone with active DSP vs an open back analog headphone (purely analog). Different devices for different purposes and preferences.

Haven’t heard the XM5s but the 3s and 4s are pretty wonky sounding without EQ, with a tubby midbass hump and upper midrange suckout that gives them a tonality I don’t care for. With EQ, they’re perfectly adequate.

Definitely not. I would not even put them in the same class.

I use a modified Sony MDR 7506 called ETA Mini Closed and a BT receiver cable instead. This solution is a lot neater than something like a DT990 Pro with a BT receiver https://i.imgur.com/p7Uymey.jpg

Not even close.