I've been using one of the chinese ones and its been fine, never missed a beat. I work it quite hard. I've got two sites i clean at now so am putting another washer on the other site. A Honda with a (i think) WS 102 Interpump. I'll check its LPM a bit later i've an idea its about 13 LPM. Thats just threw a spanner in the works for me, as im about to buy a new pump for another engine i have.
I suppose i've just got to make my mind up what way to go, 7/8 LPM pumps off the tap, or 13 LPM out of a drum. See if anyone might point me the right way.
Oh, also i used the above Honda and Interpump before off a tap, before i had considered the higher water demand, and i found it no better than the other one i have.