Ripp, on buffalo, I have found penetration to be very good and have recovered quite a few bullets. Weight retention have been pretty much 100% and they have performed superbly. I even tested a .500 triplex through the head of a downed buffalo in 06, and found the bullet in the neck, showing more than enough penetration for a charge situation. Having said that, old habits die hard and I still always change to solids when the potential for close encounters presents itself.
I also use tripleX in my 7mm over there and, once again am totally happy with them, even on eland.
I will sincerely try and get some pictures up soon.

take care,
Wadeb