Some of it depends on the climate you live in. If it's a naturally humid local, then you'll have more problems with moisture than in a naturally arid local. My experiences have been similar to Brushahhh's, but I live in southern California, and he lives in coastal Australia, so you can see the common element there. If I lived in, say, Ireland or Hawaii, I'd probably want moisture traps in every stage of the airline.
Putting a coil hose between the compressor and the moisture trap can help too. The hose will act as a condenser, making the trap's job much easier. If the trap is attached directly to the compressor (or the tank), the air will still be too warm and much of the water vapor too fine for the filter to grab. A tank can sort of act as a condenser, but it's one big solid thermal mass with a very poor surface area to volume ratio, so it's a very inefficient condenser. What makes a strong pressure vessel and what makes an effective radiator are direct opposites, unfortunately. A small tank attached to a low CFM motor will always be filled with warm air while in use, and thus will let a lot of water vapor through even if it's catching enough condensation to need regular draining.
Definataly ditch the Blue Hawks. Looking them up on line, they seem to get very mixed reviews, so I'm guessing it's not a good brand to begin with, but you shouldn't be burning through compressors like that regardless. Either they're a particularly crappy brand, or you're putting them to such heavy use that you'd be financially better off splurging on a more advanced unit with a robust warranty.
) or if really bad you could make a home made condenser to further dry the air but a filter shld do the job..good luck.
