Has anyone invested in these? Not cheap but I worked out that they should pay for themselves after 8 to 10 refills.
Having had a Gaslow system in our last Campervan I have to say that the price of bottled gas is extortionate in comparison.
Also lighter than a steel cylinder so would result in a possible recalculation in noseweight.

I have one Safefill and one Calor Lite as a standby. The only change I made was to swop the pigtail on my regulator for the safefill recommend handwheel type. I’ve had no problems although I haven’t had to fill the cylinder yet. It is nice to be able to see through the cylinder wall to see how much gas you have left. Gas is half the price though with our usage it will take a few years to pay back. The best saving is noseweight as you guessed.

Sorry. Should have said that the Safefill and Calor Lite fit snugly in the gas locker of our 420GT.

Have had a Safefill cylinder for 6 years with no problems, it is a snug fit in the gas locker.If you are going to France they do not meet the French tank regs.