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I don't know about inside, but outside the plane pushers are usually noisier, and they tend to sound really weird. I think that's because they are operating in disturbed flow which isn't the same all the way around. I seem to recall Peter Garrison covered the topic of pusher props vs. conventional in a recent column. On a push me pull you aircraft like the Cessna Skymaster, that rear prop can keep flow attached over more abrupt transitions. I seem to recall that in the column, it seemed that which one was better depended to a large extent on the details of the individual aircraft. If you could get symmetrical flow into the pusher prop, and a modified prop design, it would probably be a lot more efficient. But that doesn't usually happen. There are some neat articles on the CAFE web site of how much drag you can get rid of with axisymmetric fuselages with axisymmetric flow and a pusher prop. So just get rid of your wings. Might make sense for a dirigible or submarine. A tractor prop is going to increase airspeed over the fuselage, and, as I recall, is supposed to create bands of turbulent flow, though I understand that on something like the Nemesis, the flow is laminar in between those bands. My understanding is that the Long Eze, or perhaps it was the Varieze, was wind tunnel tested, and the prop was very innefficient, but the rest of the airframe was very low drag. The Piaggo Avanti, a pusher, is supposed to be efficient, but it sure sounds loud and weird. Canards, like many other configurations, can be quite stable. However, on a stable aircraft the rear surface must be more lightly loaded than the front. So you probably need more wing area to support a given weight, and the canard has to work very hard. An alternative is the three surface airplane such as the Piaggo Avanti. This can have, I recall reading, lower trim drag than some others. Or at least the induced part of the trim drag can be lower. If it's done right. I think wankels would show up on airplanes a lot more often if they were on all our cars and we'd been developing them for 100 years.