A/C Fittings - Long Pilot vs Short Pilot?

[LemonTwisted]

I'm trying to find out what the difference is in using a long pilot EZ Clip A/C fitting versus a short pilot fitting. It looks like the depth of the O-ring is the same between the two versions except the depth that the fitting extends into the mating part is different. Does anyone know if both fitting types are interchangeable and what would be the advantages to using one type over the other?

Thanks,