For ESC's, there isn't much that gives more bang for the bucks than the BotBitz TZ85's.

Those are reprogrammed TZ85a's from Hobbyking (or simular).
Why reprogrammed? Originaly those are brushless motor controllers.
BotBitz reprogammed them, and made a very reliable high amperage 24V esc for brushed motors. If you want something comparable, you're talking heavyweight speedo's.


Other options, if you really want 6S LiPo (Team RCC is using 3 and 4S with good results, Valkiri2* as prime example), it's not that much.
Robot Power Scorpion XXL, Sabertooth 60A, Ragebridge, IBC and RoboClaw.
Those are dedicated robot esc's that can control 2 motors in the tank style steer configuration.

If you are willing to drop to 4S LiPo, the German IBF gets my 2 tumbs up.
Handmade by a roboteer from Bavaria (Bayern, as in the B from BMW) Team RCC uses 'm as successor to the Scorpion XXL "Ilyama".


*Valkiri2 uses a 4S LiPo pack for both disk and drive.
This is one of the fights.


Reason Valkiri2 stopped. Lose wire resulting in a deep fried 150A fuze