It did OK. Power was good, though I don't have big hills to climb around here, but stability against sway makes it about as small as I'd want to go. The steering on the Highlander is a bit quick, so at highway speeds I had to be more careful than with the Jeep or the Odyssey, as tiny movement of the wheel would make it wander around a bit back there. Not white knuckle, but definitely have to pay attention. No trailer sway control that I'm aware of, even in the 2015's - that was one of the reasons I looked around beyond Toyota.
Braking was strong, though noticeably better with the surge brakes active - I did an A/B test once, just to see, with the lockout solenoid energized to see what it felt like without brakes. Ride was quite comfortable for an SUV, though you know this already. It had a 5000 lb tow rating, which is pretty good. A little higher than the 4Runner, in fact.
I wouldn't hesitate to tow mine with a Highlander again. I towed it to Toronto a couple of years ago with the Highlander, and it did fine. I do have a 2-axle trailer, though, which supposedly helps with sway (was the reason the PO's added the second axle, as they towed with a minivan). My tongue weight is definitely light, which is something I'm working on, as that will certainly make sway more of an issue.
A short-ish wheelbase also makes backing easier, as a short tractor, long trailer combo is as easy as it gets.