I had a Nautilus 500psi with 2 5.7 no APO, no Auto dump, and I normally run around 15Meters - 25 meters... Had 40 L down the carpet, and only suck up about 20L water in waste tank at the end of the job 1 wet 2 dry at least, did I use the hose too long? But the carpet still dried in reasonable time, if I finished a carpet before 12pm and it would dry by end of the night, if I have a blower on it would even dry faster I think.
Was a bit regret having a 5.7 instead of 8.4, but by our supplier told me, in our country only allow 10amp, who knows, because I have a friend using Jag 8.4 and he is doing well in any residential place, and also because I used his machine for few times so I knew quite well it didn't had any problem at all if it around 10amp or a bit over is fine, now I am trying save hard for a booster and hope can run over 30M.