We have wanted to install a Gaslow system in our caravans, but the big recurring problem that stops us doing it is access to the "Pump" in forecourts.
We have a very large unit, in all just under 13 metres long.
We could get the unit alongside our local Shell's LPG pump. However we are often away so have made a point as we travel of looking at the access to LPG pumps and concluded its not going to work out sufficiently often enough. In some cases it would require uncoupling and using the mover to get the van in place or get enough room to manoeuvre; so the attractiveness of it fades.
With a van we concluded we must have a dual system of one 11kg Gaslow plus a 6 kg Calor to cover for running out on site with awning attached.
This reduces the cost but even with our high usage its going to take a long while to recover.
IMO,if you have a motorhome and use it extensively in the winter months off EHU it must be an asset but with a big caravan it's much harder to see that it's practical.