ESC temp ?
 

I assume that ESC temp should always be measured on the heat sink? My Hydra 120 is a lot warmer on the electronics....around 150.

Depends on the esc layout- some have the heatsink directly on & above the FETs (a la MM), where as that hydra has the fins that stick out between each layer of FET boards I think? You'll get higher temps on the electronics, as the fins will drop i temp the further away from the the boards they get due to cooling down...

I'd like to figure out a way to mount the fan facing the electronics instead of the heatsink. It is running fine though.

I always check around for the hottest spot I can find on the esc and thats the temp I go by.

Yeah.