Hey Gerry.
I have a couple of those. They are pretty decent rock pickups, They have a bit of a boost in the upper midrange, to the point that they seems a bit nasally.
IIRC, Larry DiMarzio designed these for Micheal Schenker back in the 70's because Micheal was using two wah pedals on stage. He always had one on, and the pedal was locked in the middle somewhere, and that is how he got his main sound. So the PAF Pro was designed to have more emphasis in the mid range. Check out some old UFO stuff with Micheal on it and you should be able to get a good idea. Lights Out comes to mind.
On the early Steve Vai Gem guitars, the PAF Pro was the standard pickup in the bridge and neck, You can hear these on David Lee Roth's Eat'em and Smile, as well as Skyscraper albums. IF I'm not mistaken, I also believe Joe Satriani used these pickups on the Surfing With The Alien album as well.
I can also tell you a bit about the DiMarzio Tone Zone. Those have even more midrange but with the emphasis in a slightly lower frequency. Paul Gilbert used these on the later Racer X stuff, and on most of the Mr. Big albums. so you cam get a pretty good idea what these do. I have one and used it for a few months in one of my MIK Showmaster guitars, but I took it out and put in a Steve's Special which I liked a bit better. I do use the Air Zone on my other Showmanster, and I use the Air Norton in the neck on both. The Air Bucker pickups are a bit warmer sounding than their original counterparts, and sound pretty decent on these MIK guitars, since they are made with Mahogany bodies and necks, and have Rosewood fretboards. The Tone Zone just had too much mids, and not enough highs or lows for my taste.