The Metrobus did have its good points; it had pretty good peformance for a Gardner engine, and decent ride quality. But (those of certain London operators, particularly), they could get in a dreadful clonky and rattly state. I'd deliberately try to avoid a, say, London General or Metroline ex London Northern one. One other that I would suggest would be the Leyland Titan; now that was a very well designed Bus. Excellent ride quality and loads of space.