I've been on the fence on ordering the Q40 for a while now. It's pretty cheap on amazon uk nowadays.
I just recently bought a lot of headphones though (and a cat), and my wife would be disappointed so I'll probably wait a few months. It's on my list though.
I once auditioned it but I didn't like it, but it did not sound the way you describe it, or anyone else for that matter, so I'm leaning towards it being anomaly, such as the cable not being properly plugged in, or the headphones being a lemon or something like that. It really sounded horrible, and this is coming from someone who liked the XB's a lot. LOL