How does that thing work? Does it compress air to spray the paint or just pump the paint through a nozzle? I had a pump type sprayer many years ago and sprayed cellulose paint with it when I restored a motorcycle, but it was pretty hopeless because the paint had to be thinned almost to the consistency of water to stop it clogging or producing an orange peel finish.
I had something similar years ago and, for the odd job it was fine apart from a nasty habit of spattering big drops when it ran out, thereby ruining all your hard work, but this can be avoided by refilling at 1/4 full rather than when it runs out. If I were doing regular painting, I'd still go to Aldidl, but get a compressor and air sprayer. I could then justify all the nice air-driven workshop toys they have from time to time...
Have a Burgess sprayer. Great piece of kit for slapping on emulsion. Quick and easy between tenants
The thinned emulsion goes further and dries quicker. Does need 2 or 3 coats.
Also need some technique to get the viscosity right and avoid the splutter as it runs out.