The Autowbrake makes wiring easy -- it uses just the fact both brake lights came on as an indication its time to brake -- you don't need an onboard brake controller. Just 12 volt to recharage the onboard battery, which is a legal requirement.
I've also got a rav4 hybrid --- its my #3 tow vehicel -- meaning, the otehr 2 have to be 'down' before I'd use it. When I do, I lock the top speed at 60. The trailer feels heavy - I'm right at the 1700 pounds with mine (maybe slightly over? I've never put it on a scale)
I assume the prime has a beefed up braking system, stopping is what feels so squishy to me. I'm a flatlander, so I can't talk about hills. Watch your trailer loading, the hybrid anyway isn't very heavy and gets pushed around a little