I followed Bernie Baymiller's advice in building a long driver several years ago. I think I started at 47.5 inches (of course, I'm 6'6" tall, so that probably helped me adjust to it some). I could hit some real bombs with that driver, but I could miss my share as well.....my miss was high and right, more of a push than a slice. At the end of that first season I shortened it 1/2 inch when I regripped it. Every season after that when I would regrip, I would shorten it 1/4 to 1/2 inch. When I finally got to 46 inches, that seemed to be the right combination of shaft length and control for me. That was before lighter heads though. Maybe next year's experiment should be a 174 gram head on a longer, lighter shaft.....