Does anyone know how thick the memory foam is, I can see the leveltech is alot heavier but has 5cm memory foam. Occasionally I carry my bedhcairs ( due to to styles and having to reload the barrow etc..) wondering if the benchmark lite has enough memory foam to go lighter, only do the odd night here and there maybe 20 a year , single nights

I've been using mine for 3 years now. Before that I was using the standard size benchmark. I found it too hard, being a side sleeper, and also I found the leg spacing a right pain to get on the barrow. I would say the benchmark lite is a lot softer and has a bit of sag in it, which I quite like. Only negative I would say about it is that when sitting sideways on it, the bars can dig in the underside of your legs because there's not a lot of overhang on the outer skirt.
To answer your question, the memory foam isn't the 50mm of the benchmark, it's more like 25-30mm, but is more than comfy enough for me.