I received the Pix Lip and Line Primer as part of The Look Bag back in October. The shade that we received was named "Nearly Clear".
I didn't read much about it before using it but I figured that a lip primer was worth trying out. So I applied it a few times for performance under my lipstick, before lining the lips. I really liked what it did: it made my lip area smoother. It made my subsequent lip liner and lipstick application more even. I was already hooked.
Then, last weekend, I read about what the liner primer does. They say that it creates a barrier at the lip area so that the lipstick doesn't bleed. I figured that it was worth trying so I applied the lip primer first and then I applied the line primer as if it was a lip liner. Then I lined my lips and applied the lipstick. I do have another trick to prevent the lipstick from bleeding (more on that in another entry) but the result was even better than my typical trick! The lipstick looked very even and did not bleed one iota. And that one lipstick bleeds on my lips quite a bit.
Another thing that they say that the lip primer does is neutralize the lip color. That wasn't true for me but then again it's called "Nearly Clear" so, given how pigmented my lips are naturally, it probably wasn't enough to really neutralize them.
At first, I thought that the price of 18$ was too much for a mere lip primer but, after having used it, I can say that, yes, I would purchase it again at that price when it runs out. I really like what it does for my lips.