I
Ian
does that mean resin that is left in van being used daily is better ? 
Ian
p.s serious question incase I am classed as mocking which I am not.
Well I certainly noticed a difference and I wasn't even looking for a difference.
Advantages are more than the disadvantages.
For instance, no resin wastage if you forget to turn off your tap and end out overfilling your static tank.
You can also top up from a customers house if you run out of water, might use up your resin a lot faster but at least you could keep working.
Any contaminants in your static tank - algae for instance - won't get through your resin vessel.
Much easier to keep from freezing in the winter too, WCW had shed loads of window cleaners having to replace resin and pre=filter vessels due to winter freezups.
I think it is more efficient and cost effective, and I like the separation between static and van tank, if I have to waste a full tank of pure from my IBC (c
ock ups DO happen!} I know I won't have wasted resin in the process.
And as already mentioned...there seems to be far less risk of spotting.
Ian