We like our '11 Yamaha. If you're considering used and can/want to afford it, try to get the current model Drive model (2007 and newer). LOTS of improvements over prior models and the ride/suspension is more comfortable.
Yamaha uses an engine of their own manufacture - Club Car uses Kawasaki engines (to the best of my knowledge - someone correct me if I'm wrong!). Yamaha does use a 'splash' type of oiling system - it's not going to have a filter. Kawasaki's engine uses a pressurized oiling system and thus has a filter. In a golf cart application, I'd be comfortable with either engine - both are from quality manufacturers with plenty of positive history behind them. With proper maintenance, I don't think you'll wear either one of them out.
Bill
