Anecdotal comments only. My 2007, purchased new in 11/2006, has been nearly flawless. I'm driving less in recent years, but only two things have broken and needed repair in 13 years: the right front driveshaft (leaking axle boot) and the latches that keep the two rear seat legs folded in an upright position. That's a design flaw where the parts and labor quote was ridiculous so I use bungee cords to fold the seat legs up.
When I had the water pump and timing belt replaced at 9 years and 74K miles (due to age only), my mechanic told me I did it just in time because the hydraulic tensioner was leaking and soon to fail. A new one came with the Dayco timing belt kit. That job cost me $965 at an indie shop four years ago. The original Michelin LTX tires lasted 59 K miles before developing sidewall cracks. I've had one new set of front and rear brake pads, new front rotors (AC Delco Professional), two batteries and just routine maintenance otherwise. My average OCI has been 5,600 miles, which is usually about 30% on the OLM. I've used Havoline full synthetic twice but have used mostly Conoco Phillips synthetic blends (76, Kendall or Conoco). I had to use a Fumoto adapter to install their drain valve, but it was easy. Oil changes are a cinch, and mine uses zero oil between oil changes.
I have done some trailer towing (52 inch ZTR from NC to PA and a 1987 Alfa Romeo from NC to PA) with no problems. But don't mistake the Ridgeline for a conventional pickup. Instead it's got great utility and to me rides like a Honda Accord compared to some average trucks. Mileage is not the best: I've gotten as high as 21 mpg on the road and usually 17-18 in mixed driving. The new ones get better gas mileage. Most hard core pickup owners poo poo the Ridgeline, but it's been near perfect for me. At 93K miles, it's just now broken in.
Send me a private message if you have any further questions. Good luck shopping.