My lenses have seven or eight f/stops on average, some lots more, and I paid for every f/stop the company gave for me to choose from, not just for the creamy bokeh limit!
For those of you who always lug around a tripod, you can skip this post.
I use all of my f-stops and shutters as well -- when I can. But when I'm shooting IR, things change. I either have to use such a slow speed that I need a tripod or I need to open up the lens -- a lot. When I don't want the limitations of a tripod, I have no choice but to open up. Opening up is not a problem with normal film, but it is for IR.
Of course, since I always use a tripod for 4x5, this issue is only relevant to me with smaller formats -- which I use to avoid a tripod (most of the time).