"What are the latest opinions for best ESC with respect to cost, weight, and performance?"

RE cost and performance - I think Castle wins that easily.

RE Weight - make sure you are comparing weights with equal lengths of wiring, or the amount of wiring you will actually be using in your installation. The Castle comes with long wires and it quite easy to save 1 - 1.5 oz with an efficient installation.

RE Motors - dependign on your priorities, the Neu F3A-1 is in the middle of the price range of options you listed, and it is tops for power and torque (and has same gearbox maintenance requirements as Hacker inrunner).

Regards,