Just bought it today.
The girl in the shop put it on my face and it honestly looked caked on and horrible. She put a primer underneath and one of their powders on top - it really wasn't nice.
I took it off first thing when I got home and re-applied it. I used a Laura Mercier primer underneath (the one for mineral makeup) and a translucent Nars powder on top. It does settle in the pores on my nose which I don't like, but it looks pretty good. I'm not completely convinced by the brush - a Real Techniques Expert Face Brush or Buffing brush will probably work just as well.
I used one drop of it - that was enough for my face.
I got the Bare Porcelain 01 colour. It looks very good on the skin - the girl did very well colour matching me. To compare, I usually use Diorskin Nude 010 and N1 in Mac Face and Body.
I have oily, dehydrated skin and the foundation is apparently great for that skin type.
It wasn't sold to me as being more natural than other foundations and the ingredients don't look more natural than others to me.
They did say that it's made with the bare minimum ingredients and formulated without oil, silicone, parabens or fragrance (which is what it says on their website as well).
If you have very oily skin, you'll probably want to powder on top - I don't think it's keeping my skin completely matte, but now I've worn it for 5-6 hours, my skin looks very natural and luminous. Without powder, I'd probably look oily.