I use my Singers 66-4 #'s 1 & 2 about the same. I actually have 4 set up and useable but the Franklin is burried beneath and behind other machines so It's hard to get to. And the 9w-7 in the basement has my HOTHER on it cos I'm making a quilt with it.
I like the 66s because they are simple. Simple to thread, simple to treadle, and they are very easy to maintain. For the most part they are trouble free machines.
Joe