Paslode is good, but the gas canisters need to be kept warm in the colder months (i always usd to stuff one in my trouser pocket) and the cleaning procedure is a bit of a faff....
had one of the early Dewalt ones, which unfortunately broke after a few months of heavy use. some metal inside had sheared. don't know if the new ones have been changed/improved.
advantage of the Dewalt over the Paslode was the lack of gas canisters and the reduced noise level. the Paslodes can get on your tits after a while unless you wear some kind of ear protection.
there are lots of decent compressor nailers (Prebeena), but i found that constantly having to drag a hose through the hose was a PITA (i'm assuming you want it for site work). they are however super if you're working at a bench and can situate the compressor outside and insulate it to muffle the chugging.