I recently got one, and there are pros and cons.
Pros:
-It is so comfortable and lightweight, the regular size digs in a little bit at the nailhead (since it has to be a bit more fitted so the weight of the nailhead does not make it swing around).
-I can wear it all day and go running with it and never notice it.
-I think it looks more well-proportioned on my small wrist and certainly better for stacking.
-It is quite affordable.
-Over the course of a few days I thought it was warped at first when I looked down at it, but then I realized that sometimes the two sides will flip over each other and you just flip them back (it’s hard to explain, but you cross the head and tail to the opposite sides and then it lays normally again).
Cons:
-For me it does get caught on things, while I don’t have this problem with the regular size. This is because the tail is secured to the head after a couple of cm on the regular size JUC, but it is a continuous circle on the small. I noticed it would get stuck inside the sleeve of a knit sweater a few times, but that is easy to avoid if you are careful when dressing/undressing/pushing up your sleeves. The thing that was harder to control was the fact that I woke up several times at night with my wrist fastened to my knit bed sheets because the JUC had turned around and handcuffed me to the bed. So I have to take it off for sleeping, which I suppose most people do anyway.
Another pro is that Cartier’s after-purchase care is above any other brand in my experience. Any time I have ever had an issue with an item, even if it has happened once, they have taken it back and either repaired it for no cost or completely replaced the item.
So I would say go for it! Just perhaps don’t wear it to bed