I'm planning to buy this SUV sometime this year (hopefully) and have already gone ahead and test driven it. My test truck was an olive green Highlander Sport, with all the options. Unfortunately traffic was a bit heavy the day I tried it out, so I barely got a feeling of the power this thing packs: it's 270hp V6 is one of the most powerful out there (compared to the Edge's/MKX's 265hp V6, 260hp V6 on the Acadia, etc.) and yet boasts superior fuel economy and overall driving comfort.
The interior is superbly appointed, with unbeatable ergonomics and unparalleled roominess. Access to the third row was easy, even for me, and said row was comfortable enough for a drive no longer than a few hours. The driver's seating position is extraordinary, and makes it easy to drive the thing, even around heavy traffic. Acceleration is impressive, braking is too, though the brakes could be a little bit stiffer in my opinion. Handling is a bit weird and feels excessively loose as it's electric and not hydraulic, but once you get the hang of it, it's really comfortable to be able to maneuver with nothing more than the tip of your fingers on your right hand.
The back-up camera and GPS are very useful.