I have a quest 2005 and its been great so far. Never had any issues until the last 2 months. Had to replace a couple of sensors and need to replace another sensor. other than that, no major issues. its been very relaible. Big disatvantage a quest has compared to a odessy or sienna is its gas mileage during the cold season and on short runs. we normally get like 12 -14 miles/g during those times.
about a year ago the catalyst converter also went bad but the dealer replaced it at no charge so watch for that.