Reefs servos are built for them to THEIR SPECTs. Yes AFGRC builds them, as well as the Shifts, and NSDRCs etc, AFGRC is one of the largest servo manufacturers in CHY-Na. They make servos for dozens and dozens of companies.
Reefs specs are superior to those of the off the shelf AFGRC servos. And Reefs does their own software/programming on the servos.
So while they may not be the servo Manufacturer, which neither is Spektrum, Futaba, HiTec and dozens of others, they do the rest in house.
I have been very happy with using Reefs Servos, and yes, you are supporting a USA Company with Reefs, and one that supports US based events.
Its a FAST Servo, may not need that much speed. For that cost, and considering as a trail truck, off road is the thing and you may find your self crawling a few roots, have you looked into the 555? Its a slower servo but for a crawler/trail truck fast servo speed is redundant. its steel gears so it can take abuse well, and has more power, and runs up to 7.4v, maybe more so maybe a better BEC optioned servo.
Just a thought.