Single conversion receivers are slightly less 'selective' than a dual conversion receiver. Which doesn't make a lot of difference usually (only in the cost of construction). 'Selectivity' deals with 'picking' a particular signal from several in a fairly narrow range of frequencies (adjacent channel rejection). The more selectivity there is, the 'better' the receiver is at 'hearing' the desired signal from a glob of them in a band. Most modern single conversion receivers are sensitive and selective enough to work just fine. If there happens to be a 'dirty', or wider than normal transmitter being used nearby, you may have problems (actually, the one with the 'dirty' transmitter is the one with the problem). As long as the difference in price isn't much, go with the dual conversion stuff, it's just "more better"...