Base Tweakers, can anyone tell me how good they are???

[Taylor]

I know that there are 2 base tweakers that sell bases online.
This being Coach Rip and Geno.
Coach rip and geno both sell:
Speed bases
and
Power Bases

Coach Rip also sells loopers and Geno sells speed bases with the Itz dial.

Can anyone give me a review on these products? Is there discounts for ordering more than a certain amount of bases?
I'd like to know how fast these bases are.
Thanks,
Taylor