I don't know what I'm doing or what is special about my AB and compressor (Tamiya HG AB and Revo compressor), but I've never had any problems with moisture whatsoever, any time of year, no matter how long the session.
I've always heard folks say a moisture trap is absolutely necessary, but I've never had a need for one myself. I can imagine the horror of a sudden spritz of water in the mix, but thankfully have never experienced it firsthand.
Under what conditions and with what equipment is condensation buildup in the hose more likely? My Revo compressor only blows at about 11 psi. Is condensation more likely at higher pressures?
I reckon the bottom line is, if you have moisture problems, you need a moisture trap!