dual conversion receiver:

Longer range
Substantially less chance of interference (hits - ie losing your plane )


Single conversion receiver:

OK for in close flying (park flyer type )
Much less range AND SUBSTANTIALLY higher chances of interference at much over 500 - 600 '

That is the basic difference. There are a FEW exceptions to the interference/hits (Berg receivers is the primary exception ), however, I would not recommend ANY single conversion receiver for a glow powered plane since the range the plane flys at is usually substantially more than an electric.