I also have this set and I found the grapefruit scent to be the most mild, along with the cucumber water. As I understood it, Jimmyjane divided the categories up more or less by their (perceived) complexity and sophistication. Cucumbers and grapefruits are more common and accessible than rare and expensive truffles and fine bourbons. It was my observation that the two scents I just mentioned were more familiar and simpler scents that were intended to be the "safe" scents. I found that the bourbon and truffle scents were the strongest and most headache-inducing in my personal experience, and assumed many people would have a similar experience.
This just shows how subjective a thing taste is though! And allergies will correspond, I suppose! That's why this sampler is so great though. I really disliked the bourbon, but really liked the truffle and grapefruit. So now I know what I might like to invest in if I make another purchase. I know that P'Gell mentioned in her review that the lotus was her favorite and that she found the fruit scents cloying. So now she knows to steer clear of those in the future. Kinda cool, right? We're all so different, which is why it rocks to have a couple of different opinions on every review, especially with something as subjective as scent.
Also, @ P'Gell I loved reading your review after writing mine. Such a neat experience as someone that's particularly interested in taste!