When I started out as a full-time workroom, I didn't know that there were workrooms where people actually used needle and thread to sew. I thought everything in a proper workroom was done by machine. Thank goodness I soon learned differently! Sixteen years later, I've come to love sewing by hand, both for the superior results and the satisfying sense of process.
That being said, there are times when hand-sewing, while delightful, is just unnecessary because the result will be in no way superior to the machine sewn version.
So a couple of years ago I bought a blind-hemmer. When I started out, I subbed out all of my drapery orders, so I had little need for a blind-hemmer. Now, I do make some drapery, but what I make here is always and only by hand, so I still don't need the blind hemmer for panels. The same goes for my Roman shades: they are made on the table, by hand, and don't leave the table until they are on the boards.
However, I find plenty of other time-saving uses for it. It is invaluable for bedskirts, a few valance applications, and, sometimes, relaxed, London, or balloon shades.
It made short work of this interlined London shade.