I definitely used a Panther back in the day. of course, I had a couple Rocs but I bought a Panther because the stamp was awesome and it was the only black disc at Bob Wards at the time. I don't remember much about it, but I did throw a Champion Panther a year or so ago and just didn't care for it. It didn't seem to have the same feel that I remember but that was ages ago..
I also don't see them around much anymore. Honestly, it's just way easier for my to find Tangents then it would be a Panther...and like I said, the Panther just doesn't have the feeling that I remember. But if I recall correctly it was one of the earliest Innova discs made with all-Pro input...basically they made it because their pros wanted it. So I know it was a bag stable int he early to mid 90s for a lot of Pros.