Allowing one to reduce the range of the volume control (or peg it at 100% so you don't accidentally set it to 117% or having to live with it at 98 or 105% because you can't get it back to 100%)
This was driving me nuts. I finally figured a way around it though. For me, each click of the scroll wheel moves it by 1/8, so 8 clicks from the highest or lowest value puts it back at 100%. Scroll wheel all the way to 0 (min) or 200% (max), then scroll wheel back to 100%. It will hit it on the nose.