As an update on this I bought some hb body epoxy and was impressed. Build was good and it flatted beautifully with p320 abranet. Would say its far superior to cellulose high build and on par with my normal 2k high build. Never bought any water based to try but after this don't think I will.
Daz according to the lad who runs the paint suppliers near me, HB is good quality and he has never had any trouble with it. I was going to buy it but it was the cheap price that put me off lol.