OK, I've been listening to the Mad Dogs for a while while enjoying an awesome Fresh-Hop Imperial IPA from San Diego's Stone Brewing:
I've run through tracks from a few different albums, in different genres, so far:
Tuck Andress: Reckless Precision
Jaco Pastorius: Jaco Pastorius
AC DC: Back In Black
Albert Collins: Deluxe Edition
Diana Krall: The Girl In The Other Room
Red Hot Chili Peppers: Californication
On each of the tracks I listened to from these albums I switched between the Mad Dogs and the Sony MDR-V600's, which I've had for over 20 years. The overriding difference I notice on just about every track is that the Mad Dogs are more "solid". By that I mean that the sound is more full and substantial. When called for, the bass is plenty solid but not boomy. Based on hearing Diana Krall in both headphones, if I were a single guy, I would definitely be more likely to want the Mad Dog Diana Krall over the Sony version. Her voice was a whole lot more sensual and sultry through the Mad Dogs.
Overall, compared to the Mad Dogs, the MDR-V600's were a lot "thinner" sounding in comparison.. Everything seemed to be floating in a cloud. The Sony's are a more efficient headphone so I'm sure that makes a difference as far as perceived loudness goes. The Squeezebox is able to drive the Mad Dogs but just barely. I'm definitely glad that I ordered the Schiit Magni because the Mad Dogs seem to need a decent amount of power.
Overall, after about 3 hours of listening, I'm very happy with my decision The sound I'm getting through them is solid and spacious without being "otherworldly". Everything seems to be where it should be in the sound stage. The Mad Dogs are a little bit on the "dark" side as far as sound goes but I'd rather have that than too bright, which is what my old Sony's are/were. Build quality seems great and comfort is, well, comfortable.
No complaints so far and I don't expect that to change any time soon. I think I made a good 1st choice in an audiophile quality headphone. Two thumbs-up!