I've got the smaller 45 litre Webasto and have been pleasantly surprised at how cold it gets, the little freezer box freezes ice cubes and an additional cooler block.
I leave it on all the time now, even when I'm not using the campervan as the
solar panel is producing enough power to keep the 2 x 100aH batteries up to charge. Overnight they drop to about 12.8V, during bright sunlight they are fully charging at 13.8V.
I added some additional insulation (silvered foam) to the exterior of the fridge, so that may help as well.
Got home yesterday after a quick run down to Coffs Harbour (in Australia), temps in mid thirties Celsius and the fridge was fine, whereas the cab AC was struggling with the high humidity and was icing up.
I used to be an advocate of the RM series of Electrolux fridges, but in the 70 odd years since they were introduced the technology of the 12V compressor and solar panels has leapt ahead, you don't need to have a 3 way fridge now to go long periods of being on the one site as long as you have solar panels.
I don't have any gas appliances - just diesel and 12V - which is great as you don't lose space to a gas locker or underslung tank - is far cheaper as any competent person can fit diesel appliances and they don't need certifying annually or ten years on LPG tanks.