I know it isn't HiFiGuy's response, but Tyll at InnerFidelity compared the two:
I think his criteria were a little different than what HiFiGuy is after though (he seemed to focus more on how well the ANC worked).
Maybe the Mixr or the Pros can cut it, but other Beats won't. Even most modern hip-hop uses more advanced full melodic range sounds that Tours/Solos/Studios IMHO fail to deliver without giving a headache. The bass might be OK, but anything above 1000Hz will sound like a needle in the ear and needs heavy EQ-ing (up to -6db) to make it listenable.
Just listened to some bassy tracks - tech house, hard techno, jazz, blues, rap, classical with my Tours. As far as the majority of sounds stays in the bass - everything sounds great, but when things go beyond…. Even a single hi-hat every beat can be irritating.
I know you asked about the Beats Pro, but all Beats share this sound specific more or less.
Which one is the "Tour"? (I don't keep track).
And when you say "needle in the ear" you mean they have piercing/shrill treble? Along the lines of what? T70? SR-325? etc