"1.5 is heavenly and a lot less labor."Jet size is one part of it, the rest depends on all the other parts. 3/8" solution hose holds double the amount of water already pressurized, this is large. Test your equipment and see where you are at. Removing all your jets and measure flow through the wand for an idea of your system gross output in it's current configuration vs open flow with the same amount of solution line. This will help you determine what to upgrade. 1 gpm is not ideal, 1.25 will be great, 1.5 is heavenly and a lot less labor.
And, I think you mentioned guys with lx machines (air hog lx) can recover this increased flow without creating longer dry times. If so, sounds like something worth pursuing.