I have also been using the one that Paul Moss has, i have had several different one and this is by far the best so far.
I hardly use my inline sprayer these days. saves fuel, prespray is dwelling whilst setting up truckmount, just so much easier. On large jobs people can go to the next floor whilst you finish another. I also have difficulty in mixing some of my recipes into a 4 ltr concentrate as well, so it does save a lot of time. I do attach a different spray wand for upholstery though but still use the battery sprayer, handy when doing a lot of upholstery or curtains.
Peter