At around £3-£4 it's worth trying. The only downside is it can be quite drying on the skin so layer on the moisturiser first. Pay lots of attention around the elbows, knees and ankles as these are my most dry areas of skin. Surprisingly my underarms also have dry skin, so I layer on the moisturiser under my arms... it sounds weird but it also stops the fake tan settling in your arm pits which is a no-go for me. Putting fake tan on your arm pits makes you sweat excessively as your blocking the pores.
I have always used the original formula which isn't too dark and you can put extra layers on the next day if you don't feel dark enough. So when I saw they had come up with a 'Dark' option I gave it a go.
I was surprised to find absolutely no difference at all. If anyone feels differently please say because I am struggling to see a difference between the two at all.
Left: Dark Right:Original
Surprisingly the right hand side, which I think is the darker foam, is the original formula. I would say that either formula is going to give you pretty much the same result.