That's a great idea (changing from "Modern" to another style, whether Silver/Classic/System/etc.).
I don't think a different style can ruin a UI, just change it.
I prefer this over the "custom" control solution just because I'm trying to keep this as a stand-alone file.
It's still too bad that there's a property in there that can't be edited.
I guess you never need the increment/decrement. I originally took them away, and then added them back in as I thought about how users would want to most conveniently adjust the values. Then I started my search for resizing, which brought me to this thread.