Oh dear - you know not what you have stirred up. World wars have started over less controversial issues.
My personal view, of course, but the answer to your question is Double Boiler machine, without question.
I've owned singe boiler machines (cheap ones) an HX machine, and now have a double boiler machine, so think I can claim a valid perspective (as a home user, anyway).
As between HX and double boiler, I just find the latter so much simpler and easier to use. I could never master the black art of the cooling flush - possibly due to lack of effort on my part, but have you actually read the procedures some people go through ? I'm a simple soul, and just want a cup of coffee, requiring the least possible effort consistent with a good cup.
Having paid a fair amount of cash for it, I really wanted to like the HX machine, but I could not get on with it. I sold it and would never go back to one. I wish I'd never bought it. I'd buy a single boiler machine in preference if I had to.
There must be a fair few people on here able to make real life comparisons, having owned or had significant use of both types of machine, so hopefully they will comment too.
Better batten down the hatches and wait for the outcry I reckon......
Please promise that you won't ask whether you should get a doser or non-doser grinder or we shall have more bloodshed.
