My 2x12 has taken a battering and has been fine, I will mention that it's shock mounted. Current wise it has an overload cut out so if life gets a bit much it will current limit and so on. There is a red LED on it that flickers if this happens, but I only run the most basic of robots on 14.4V argos drill motors that only pull about 7Amps a side so have never had a problem. If you were moving up to beefy drive trains you'd need a 2x25 or an XL and so on. If you're only running cheap drills you'll be fine with a 2x12, but if you intend to progress to Torpedo 800's, Banebot's 775's and so on in the near future spend your cash on something heavy duty to start with. I can only afford to build basic drill powered stuff at the minute so my 2x12 suits me down to the ground for the time being.