I've been hoping for an ESC that could be daisychained to a "master" ESC for some time now. Would solve the whole dual BL motor syncing issue to keep them at the same speed despite slight differences in motor kv or whatever. Making a 4WD Slash would be a simple matter then.
I would love for castle to make a speed controller to compete with the large MGM 40063 or 25063, or the 40.330 from schulze. Yes the controllers would be physically bigger than what they are now but 400A constant at 63V and 500A burst