Well I gave this beast a run yesterday and It took one of my tyres 15psi to 30psi in under 30 seconds and it will do 33" tyres in under a minute, At first I was not sure about it then I used a stopwatch and the thing is a Beast, I have used normal 240v compressors at work everyday and this thing seems faster than compressors up to 14,7cfm at blowing up tyres, Maybe it has a lot to do with the Tyre Gauge but either way it is seriously fast, The only thing faster would be a Co2 bottle, Expensive ? sort of but it will do tyres over 37" to 42"ish and it will take a 35" from 15 to 32psi in under 1min 15secs. One thing I did notice is where other compressors slow down as the pressure goes up this thing accelerates faster until it reaches it's max speed.
If I was using Tyres that were 33 to 35" then I would go with the Normal ARB High Output single version, 1) it's a lot lighter to use 2) It is compact, 3) It's more than fast enough and it can take a 245/70/16 = 9.50x 29.5" from 15psi to 30/31psi in 1min 03secs and it will take a 35x12.5x17 from 15psi to 32psi in 2mins 10secs which is not too shabby, If you would be happy with those times then that is the one to get, And I think that the High Output Single version is nicer to use and although I also own a Generic Twin and the ARB Twin, The ARB Single is by far my favourite and only In extreme cases would you need the Twin or you just want the best of the best.
But the Max Power Twin is a Beast Yes it's fast, and it is about 2.5 times the price of the single, One thing I don't like is when you pick it up by the handle it seems to be heavy at one end, Another thing I noticed was when you first turn it on make sure you connect the Pressure Gauge/Tyre doodad to the hose first before plug the hose in to the compressor because when it has 150psi in the Tank it is a bugga to try and connect the Gauge to the hose, and then plug the hose in to the compressor, Or connect it all up before you turn it on would be even better, Also when you have finished using it Turn it off and then let some of the Air out of the Tank before trying to disconnecting the hose etc by squeezing the trigger on the Gauge because it could Blast Air or Dirt in to your face or eyes etc, No Joke It really comes out with a wallop. So be warned.
Hope that helps.
John.