OK here’s one. I got some Surface Headphones free from Microsoft and used them for years. I started to think about an upgrade to audiophile phones and auditioned some Focals, Grados, and the HD6xx. I was very surprised to find how good the Surface ones sounded in comparison. Maybe my ears were just so used to the sound after thousands of hours of listening but I’ll say that those Bluetooth, office focused closed-backs don’t sound too bad.