Almost every top studio has one (Distressor), usually more than one, because it does so many things so well whether tracking or mixing. And they aren't all that expensive either - usually around $1100-1200 for one channel.
The Fatso Jr. is a little more of a specialized unit. Because of the lack of fine control over compression parameters, I was not able to get much use out of it while tracking, although that could be a function of my skill level. Typically it is used as an insert into the mix bus to put a little bit of analog compression sheen on an otherwise mix, similar to how one would use the Cranesong HEDD, except the HEDD has no compression functions.