I wasn't really happy with the depth control on the nailer since there's no indicator (at least the compressor has a pressure guage). I do wish the compressor was quieter, or started up slower (it scared the hell out of me when the pump automatically refilled the tank, even through my earplugs). But the build quality is excellent (the tank welds are top notch).
Shipping seems to be a problem - I received my nailer/compressor combo today. The foot rest on the end of the compressor tank was bent.

1) Noisy compressor,
2) Gun does not warn user when it runs out of nails,
3) Should have provided 2-1/2" nails, rather than the 2" nails,
4) Compressor's auto on/off lever can dislodge from the switch assembly when the lever is pushed/pulled at the wrong angle,
5) Must order the free black coloured trigger separately,
6) The gun will at the odd time spall the MDF moulding surface at the nail's point of entry (which means more caulking).

I have owned this compressor for 4+ years now and am still completely satisfied. I used a hand held, air chisel to break up the mortar joints. The compressor was operating at 100% duty cycle for 10-15 minutes at a stretch, but couldn't quite keep up with continuous use of the air chisel. As an last ditch experiment, I bought a 10 gal portable air storage tank, some extra quick disconnect fittings and rigged up a reserve tank in parallel with the 4 gallon PC tank. (yes, I am an engineer) My thinking was that I would run the crap out of my little PC and if it bit the dust, that was my excuse to buy a new compressor. I am amazed to say the PC compressor ran flawlessly for the entire chimney demo and still works fine today.
Poor Engineering - There is no gauge guard that would prevent the whole gage assembly from bending (and separating) at the base where the nipple attaches to the tank. Air will leak from the threads of the nipple (as was the case for me) or worse. Pancake compressors due to their top heavy nature can and do rollover, and if this unit rolls onto the gauge side, sooner or later your going to have a major problem. I discovered this design flaw when I plugged my brand new compressor in and a rush of air shot out where the gauge nipple screws to the tank. There was no visible damage to the gages so that means to me that it doesn't take much of a blow to damage the nipple-to-tank connection. The compressor was improperly packaged. There was no extra packing foam or otherwise to prevent the compressor from banging side ways.
Great machine - The problem was, there were a couple `for' and a couple `against' this compressor which didn't help in the decision process (usually there's enough positive or negative comments to aid in making a decision). mechanical but that's completely irrelevant!) about the gage guard and the connection at the tank and yes you could easily break it off. If you want to ensure you don't have this problem, buy a compressor with a cage around it. Heck what do you want from a COMPRESSOR!

- Plenty of air to shoot my 15ga nails and recovery time on the tank is VERY quick.
Damaged Compressor due to defective design - My compressor arrived damaged due to the gauge assembly being bent during shipping resulting in the nipple to the tank splitting open. The compressor was unusable. After thinking about it for 30 seconds, I realized that this compressor can not stand up to any damage on the job and moreover may represent a situation where the gauge could unexpectedly blow out and kill/injure someone.

I recommend buying a different compressor.
A great portable for small jobs -

Even with these drawbacks its a great little compressor for finish carpentry.