I tried a friends Earthquake, its not bad but a little low on power and definitely overweight, even the old IR 231 which a lower power gun beats it handily and the Aircat is in another class altogether, almost twice the power and almost half the weight.
This guy is a working mechanic a DIY special isn't the grade of tool best suited to his needs, the Earthquakes weight to power ratio make it a home garage unit for small stuff at best.
Then there is the warranty and repairability, this is where the HF really falls flat. 90 days with no repair kits.
Aircat has 2 yrs full parts and labor with kits inc motor blades available for around $25.