Quark roadster here
When I was pushing a 666w monster (Jae introduced me to trying new motors really. His list of comparisons racing multiple motors on the detta was inspiring), 3 A123 2300mAh cells and a 3200kv 28mmx56mm can...
Still I do feel safer using this than using my mamba or even quark when I'm pushing higher voltages on larger/faster motors.
I'm definitely going to be investing in a sidewinder system. It's not the amperage of the mamba max, but it's nearing that league with the ability to push 540 can motors up to the 5700kv mamba.
NOTE - If amps and how much a speed controller can handle seems like dark magic :
amps increase with voltage - so 2 lipos being the limit on a mamba 8000kv motor means that's the amps it should take.
amps increase with the decrease in motor resistance. less winds = more kv = less resistance = more amps.
amps increase with larger can motors - a large motor like the ammo 5100kv 28mm draws much more than the 5400 mamba.
amps increase with cogging! If you're cogging you're wasting FAR more power than you may realize, as the motor jiggles itself around.
amps increase with load - a heavy chassis, binding of drivetrain, getting stuck in mud/rock and forcing yourself out (beware rock climbers!), constantly accelerating and braking, wheels too large, gear too high. If you motor works harder, there's a lot more current than free rolling.
Even if you're running a motor IN spec, and you're cogging, forcing your wheels free when stuck, or stopping and starting roughly, you can damage the esc. Even if you're motor is out of spec, but you're driving well, smooth drivetrain, smart choice in gearing, you should be ok!