hi marcus,yes i have one,you can,t use it as a back-pack due to the weight,so you tend to carry it about,also due to the fact that there is no flow controller on it, if you turn it on you,ll empty the tank on about 2 windows,so what i did was to put an a tap, and i am able to controle the flow rate by that,you would be able to do the backs and maybe side of a 3 bed-semi with a tank which is about 10ltrs,so you,ll have 8ltrs left,i do use it quite a lot,well worth the money...kev