I use Split Grade printing for the majority of my work. It makes sense to me. I use a condensor head with mg filters, and I do find I can get my prints to states that I do not feel able to using the intermediate filters. contrary to Nicholas's statement above, I moved on to split grade after struggling for ages with using single grades - I feel it was a progression to do so and my printing improved as a result. As already said, fine highlight details, mids and shadows are all controlled in the hard grade exposure(s).