Downside is no directions as to type of oil, how much, bolt pattern, break-in and things like that. I was worried about the packaging as a lot of them arrive damaged and I can see why. Mine came wrapped in some white foam, but I was lucky it was not damaged. A few of those air bags would have made the packaging much better. It took forever to put the oil in it (it takes a quart). Pour it in through the orange relief valve SLOWLY. I used some synthetic compressor oil that runs about 10 bucks on amazon. I ran it for a half hour with the valve open to break it in like my DeWalt said to do on my other compressor. This pump replaced a pump on a Husky 60 gallon tank. Mounting was not a straight bolt-on, but if you are using a compressor, you should have no issues with this. I had to redrill the mounting holes for the pump and the motor. Rerouting the line from the pump to the tank just required a couple of compression fittings and some 1/2" copper tube and pipe bushings I had laying around. I like the cooling fins on the discharge air to the tank. All pumps should have that. The flywheel was aluminum and very light. I consider this a plus as it cools the pump as it spins and reduces start up torque. The pump did not get as warm as I expected. I had a 3.5 " pulley on the motor so with the 10.5" pump pulley, it took a little bit longer to press up, but not bad. Quieter than my Dewalt, but it's not working as hard either. I plan to hook the two compressors together for a large reserve of 120 gallons and lots of airflow. The pump says it will press to 115 psi, but that is really dependent on the set pressure on the control. Mine runs to 125-135 psi before the pump shuts off. Time will tell if the unit holds up, but initially it seems like a good buy. I would like to know how the one reviewer actually contacted this Happybuy place (and got GREAT results) as I could not find any contact information at all.