I had a mutant cell, I think the 715T drilled to roll a bit weaker(2000AB) will match up well. I cant see a 715C(pearl) match up good, it wont handle the oil as well.
The 505T drilled a bit more aggressively and sanded to 2000 would do the trick too!
I have both 715T and 505T, both are excellent balls and more consistent than the Mutant Cell.
I have drilled the same, 505T at 2000 and the 715T at 1000. Gives me a good look on all heavier to med hevy conditions between the two of them.
When both are at 2000, I see about 3-5 boards more out of the 715T. The 505T has been money for me on THS!! The 715T is a bit strong for THS IMHO after the first game. I prefer the 505T at 2000, it very smooth and predictable and reds the lane well, its also pretty versatile and carries from every angle!
My Current Arsenal:
715T................... 65x4.4x30 1000AB
505T................... 65x4.5x30 2000AB
Bank Pearl...........60x5x40 1500 polished
Dark Star.............70x3.5x40 1500 polished
Red Backlash.......75x3x35 2000 polished