Ehab:

I see your point, and yes, a bit of residual thrust is good. But in the case of thrust reversers, they are not deployed until the aircraft is already on the ground, after the point that a go around is no longer an option. They are used in conjunction with brakes to slow the aircraft. In all actuality, they would not be of any great benefit on our models, except for greater scale authenticity on some aircraft. Even at 30 or 40 pounds, a turbine model is not hard to stop once it is on the ground. Airliners and other large aircraft use them because of the weight of the aircraft, and the rolling mass that you are trying to slow down and stop. Using brakes alone, it is hard to shut an airliner, or even some corporate jets on the shorter runways. I dont know of any military fighter type aircraft that use reversers. Some of them use thrust attenuators and drogue chutes, like the F-4, F-15, etc. but only the heavy iron like the KC-10, KC-135, AWACs, and large transports use actual reversers on their engines. It would be pretty cool to have a set on a scale model that actually work, though.