I already own Ormonde Jayne Osmanthus in the shower creme and body lotion, as I like to wear it layered underneath the darker Ormonde Jayne scents I own; it's particularly good underneath Ormonde Woman.
Osmanthus has an effervescence to it; it's a crisp sparkling citrus with herby notes. I don't find it overly floral, and it's a very work-appropriate fragrance in my opinion. Even though it is uncomplicated, it still has the Ormonde Jayne accord that I like, and it's definitely not a soapy/generic citrus scent. Linda Pilkington (the nose behind Ormonde Jayne) recommends it for hot countries and hot weather, and I totally agree with that recommendation.
To compare Osmanthus with Champaca; Champaca is sweeter and creamier, Osmanthus is more sparkling and herby. Both are lovely spring scents.
Summary - a glorious herbal-citrus scent. I tend to like these types of scents primarily as layering shower/body products underneath other fragrances, and Osmanthus is excellent for that purpose. I'd recommend both the bath and shower creme and the body lotion, which Mr London has given me as gifts in the past (these are paraben-free, which is useful to know if you're trying to avoid parabens). It's also a lovely fragrance in its own right, for citrus lovers.
Ormonde Jayne products can be bought at the Royal Arcade boutique in London, and online at www.ormondejayne.com.
Disclosure: fragrance sample reviewed is part of Discovery Set, sent without charge for consideration for review.