It towed really well and I hardly knew it was there. I mainly stayed at 55MPH on the freeway. The Lock n Roll hitch was really quiet. When I pull the trailer I won't need to have the AO Rack on at the same time so it will help with gas mileage.
I agree, the Lock n Roll hitch is very quiet. We use locking hitch pins with ours, on both the FJ and the trailer. I have not pulled it with regular hitch pins, so truthfully I'm not sure how much difference it makes, but it's much quieter than any other trailer I've pulled.
It will be nice to be able to pull the roof rack off if that's easy to do. So far it looks like towing the Horizon costs me at least 3 mpg at freeway speeds, but I'm guessing your trailer may be lighter than a Horizon (base weight = 1100# + options).
And +2 or +3 on the Tekonsha Prodigy brake controller. It's been working well for me so far and it was a pretty easy install. The biggest challenge was finding a good location to mount it since it needs to be somewhat level. I think the spec was +/- 70 degrees, but you need to take steep descents into account.