I took the compressor to the local Porter-Cable service center and they tell me the boxes the P-C compressors come in are NOT designed to handle the rigorous treatment of UPS shipping.
Poor Engineering - 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.
A good compressor to get you started. - this model comes in at about the mid-range of the portables.

Other than that what can I say - it pumps air. It is fairly loud, but I haven't listened to many other models to make an educated comparison. I have used it quite a bit for high air flow operations, such as blowing off dust / debris and even running an air chisel to bust up concrete. It often runs full time for 5-10 minutes and is able to keep up with air demand. I actually ran a compressed air line out to my garage, so the compressor can stay put in the basement and avoid potential damage from moving it. 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.

Looking at the other brands of portable compressors I really like how well this one is built.
Darn Good Little Compressor - Short and sweet - this compressor delivers on its promises - it is easy to use, easy to break-in, easy to maintain, and you can't beat the duel air hose inlets. I have found both of the built in pressure gauges to be accurate, and the oil-free motor is quieter than other compressors I have used (although it still makes a good bit of noise). To me, that's portable - I can understand how that would not be the case with everyone, but my experience leads me to believe that this compressor has a very good weight-to-horsepower-to-air storage capacity ratio.
Great General Purpose Portable Compressor - I bought this compressor to run nail guns, air sand and spray paint. It is also handy to limit the pressure to safe levels for your various air tools. Shut it off, close the valve and turn it back on; you're ready for action! The unit really is portable, especially with the well balanced carry handle protruding from the top. It is not as loud as large upright compressors, but it does make a fair amount of noise, although not as much as I expected. I use it with a Souix air sander and it does run longer when I am working.
This is a SERIOUS compressor - Desipite its small size and minimal air tank capacity, this is a very serious commercial duty air compressor. AC induction motors like the ones found in this compressor are far superior to brushed AC motors found in most "consumer" air compressors. Because of this motor, the compressor is able to deliver air flows similar to larger 15 gallon compressors. Aside from air sanding or heavy duty HVLP paint spraying, there is nothing that I cannot do with this compressor.
THIS IS THE ONE !!!! - I have had larger compressors, but this little guy keeps up with want ever jobs I have for it.
Great little air compressor - This air compressor is great! This unit is fairly quiet, compact, light enough to be toted around if needed, no oil needed and very powerful. This unit replaced a 12 year old 15 gallons, 2 hp, craftsman rolling air compressor and all I can say is that I wish I purchased this unit sooner. I like the portable size too, it doesn't take up too much room. I consider this a plus though, because I always drain the tank after each use and it does not take as long to release all the air. At this price range there are many choices out there for anyone looking for a compact air compressor but when you start to compare CFM ratings @ 90 PSI this one has the highest ratings.
Excellent compressor - quietest I've used in its category - I am never able to live without a good air compressor. I use them for a variety of tasks from simple blowing to nailers and air hammers. As smaller air compressors go, this one really delivers a nice, steady pressure for quite a long time.

Normally I like to blow through my air gun at about 50psi to clear sawdust. Blowing air at that pressure really drains a small compressor fast, but this one really handles it well and gives me quite a bit of extra time due to the fact that the motor really kicks in quickly and efficiently to keep the pressure up.

The two air ports is really nice in one this size because I can put the compressor underneath my workbench and mount a static line on my workbench for easy access anytime while leaving the other open for longer hoses. These size compressors can make an INCREDIBLE amount of noise, but the Porter-Cable 3hp 4 gallon side stack really keeps the noise level at a minimum.
Better than the pancake model - The only thing I don't think is an improvement is the knob for adjusting air pressure.

This time I installed the compressor with the air hose reel from Amazon mounted right beside it on the floor. I now use the pancake style as the portable one (I agree, this one's too heavy).
Don't let the handle fool you. - I know now why most compressors this size have wheels. I wanted an air compressor that could inflate tractor tires and power air tools. I recommed this to any one looking for an good air compressor that stays for the most part in one place.
Fantastic Compressor - I was told by others that none of these smaller compressors would do that.
Heavy Duty versatility - I run one in to my garage for airing my tires, and one in the shop for projects.
I will tell you it is LOUD but so are all compressors in this class, and this one is not as loud as my last old Campbell-Hausfeld.