Rob, it sounds a bit like to me that you are operating more out of a small business model. Clients come to you mostly. Whereas, some of these folks are working under a "for hire" freelance model where someone else has the clients and needs additional manpower/talent to get it done. In those cases, the in house freelancer can command less of a day rate than someone who has sought and maintained their own client and equipment. Even though we tend to toss the term freelance around pretty easily, I think a lot of folks who call themselves "freelance" are really just small business owners. Both methods have their merits.
I am also encouraged somewhat by Rob being able to fetch a livable rate. I assume you are no spring chick Rob(in a good way) and I think it's good for our industry to have seasoned talent doing quality work. As I get a little older, sometimes I fear this is a young man's game and I'll age out at some point. Staying sharp is a constant concern of mine now that I have a family to look out for.