I've never used them and, personally, I'm not the hugest fan of brush sets overall. (I've made exceptions and bought sets in the past, but I've generally ended up liking/using only a select few and wishing those few were available individually.) In general, if you buy a set, you'll inevitably end up with some brushes you'll never use. I think a better idea is to determine which individual brushes you think you'll use all the time and buy those ones.