So I own a 50ml bottle of Une Fleur de Cassie by Editions des Parfums. I consider it a true masterpiece and a truly challenging fragrance.
I wear it, albeit infrequently, when I am in an avant-garde mood or if I'm feeling creative.
Farnesiana by Caron, is a fragrance that I have long since admired and I appreciate the fact that Ropion and Malle may have been inspired by it when creating the aforementioned work of art. To my mind, it is far more delicate than Une Fleur de Cassie and more apparently beautiful.
So my question is, should I invest in a bottle of Farnesiana or will owning it take away some of the impact of Une Fleur de Cassie? Will I find myself using Ropion's creation far less as a result? Hmmm.
I would avoid the edt - seldom a good idea with the Carons. I have the parfum. I have never smelled vintage, from the descriptions, the current parfum should be more sedate and sweet, but I still like it. It is very different from UFC, though, it's definitely a typical heliotropin, sedate, smiling, quiet, as you point out, more Eau d'Hiver than UFC.
Incidentally, I read that UFC has itself been reformulated, being much cleaner now.
Malle's Une Fleur de Cassie is the benchmark if you want mimosa/cassie IMO. It has been changed slightly. The base is now cleaner and the dirty weird cassie note does not last as long in the drydown making it a bit too 'polished' in the deep base for my taste. It's not drastic, but it was better than it is now. I first had a 50 ml bottle of the newer jus (the color of which is very light) and I am now on my 100 ml back-up, when I happened to be lucky to get an older (color is orange-ish, light-amber).
Now Farnesiana starts off with a clear mimosa/cassie note, but with a much broader story to tell. It veers towards Shalimar and even Ambre Precieux territory in its drydown. It is very unique and entertaining, however it never was one of my favorite Carons. I have a tiny sample of old Farnesiana and to me new and old clearly smell like Farnesiana - not a great difference at all.