We recently sold a 2012 that we used to tow a 19 foot Airstream. We used sway control but no weight distribution. Be aware that weight distribution should not be used unless you have a hitch from Lexus. Other hitches and OEM hitches don't attach to a frame rail therefore can't withstand the constant flexing.
As a tow vehicle it was stable and got fairly good gas mileage. I would suggest limiting the length of your tow to 19 feet. We had the 6 cylinder Limited.
