We bought a Yamaha Viking last year, and it has been great for our purposes. It is not the fastest (52 mph max) or quietest (engine and somewhat "squeaky"), but it comfortably seats 3 across and meets our needs for tooling around in the national forest. It has good engine braking on the downhills and a differential lock when needed. We do keep an older quad at the cabin in case we want to go on 50 inch trails. The OP asked about roominess. The seats do slide front and back, but you bolt them down when adjusted. My wife does not find that convenient.
