Does anybody still use them? If so what situation would you use them for? What are your likes/dislikes compared to DT or WF lines of today?

I started fly fishing with one many moons ago but very shortly thereafter gave up on fly fishing. I actually got to cast real silk one time. Casting silk is an experience all fly fishers should have at least once in their lives. When I started back into the sport again we had all of these fancy new lines and tapers. As I recall level lines were much harder to cast for distance but could make a very delicate presentation. I was considering trying to find one for my 7wt glass rod.