I've had several Sabreteeth fail on me, and for little or no reason, but their customer service is brilliant and they replaced/upgraded free of charge on all occasions.
They also have some nice built in features like, mixing, thermal protection, current limiting, they're a dual controller (smaller, lighter, mounting plate) acceleration ramping, calibrate-able fail safe etc....

The BotsBitz (although I've never used them) have a higher amp rating, built in braking (very useful, not on the Saberteeth) and covered PCBs.

Prices work about the same though I believe? So up to you.