I'll start with the original... This primer differs from the next two I'm going to talk about as it dries transparent. It helps to even out the skin tone across your lid but wont add any colour. This is one of my favourites of the four. I think this would be a good one to go for if you tend to wear different types of eye-shadow as it would work for shimmery or matt shadows.
Next is Eden. I'm really torn between this and the original primer. This primer dries a nude colour which I find is really great as a base and helps to make nude colours stand out a bit more. It just kind of gives you a clean slate to work with. It is matt, which is great for me as I tend to stick to matt shadows on a day to day basis. If you're into your shimmers and glitters then this might not be the best for you.
The complete opposite of this is the third primer, Sin. This is a shimmery primer which is a pinky colour, its actually similar to the shade Sin in the first Naked Palette. This primer really helps to make shimmery shadows pop and look that little bit more shimmery. It's actually a really nice colour all on its own!
The least used primer was the Anti-Ageing primer. I didn't use this much simply because it's not a prouduct that's really aimed at my skin type. It is similar to the Original primer because it dries transparent. Its a different texture which actually makes it a little easier to apply. This is thinner and less tacky than the others, this feels more like a moisturiser. I don't know if this has any effect on the staying power of the shadow but it seemed to work just as well.