I got a plain gold JUC around 4 years ago and recently bought a diamond tip one (both are regular size), and both are the same in terms of thickness. However, when I bought my plain gold one (4 years ago), I thought it looked thinner than some of the older ones I had seen and tried (especially the old lock ones). Recently, I tried on an old lock one (from 2016), and it was exactly the same as my plain one! I think our eyes keep playing tricks on us! Having said that, I do feel that smaller-sized ones look chunkier than larger ones (my size 15 looks heftier than my size 16 one when worn!). Sorry if I confused you even more! haha