Thank you very much for the replies guys.
My client saw the first site (fressko) and they became attacked to the swipe parallax effect. But the problem is, that it's supposed to be a responsive website.. well those parallax effects don't really work on mobile at all. Not to mention the flasks need to flow under one another for mobile. It's really confusing me which way to take this.
So, I created Freshko (the second example) without the full page fixed background images. I was hoping I could re-create the swipe effect of the first example on the second with GS. But maybe that's not possible.
Thank you for your example though, I am reading through that now. Do you know how that would go if run on a mobile phone?
In fact - does ANYONE have a single example of fixed background working really well on mobile? I've never seen one. The scroll events always get updated after the user stops scrolling on a mobile.