I'd buy the RX even for a significant premium. The advantages the VW has like better handling, less common and/or euro interior aren't as important to me as the better reliability of the Lexus. But that's a personal choice. RX shares platform and drivetrain with the Highlander, parts will never be a problem and it's reliable due to the large volumes they were designed to be sold in. The 3.5 is a great engine, only real issue was a rubber oil line which wouldn't be an issue in the 08+'s you are considering.
The RX can tow 1500lbs no problem, I'm sure the VW can too.
FWIW our Highlander is the least fun to drive car I've ever had, but one of the best. I'm not sure I could ever own a non-hatchback car again. The amount of stuff you can cram in is amazing. It's only been 104,000 miles but no stops at a mechanic yet.