Since 2009, I’ve reamed and slotted all of my pin-bridge guitars’ pin-holes and installed solid pins. I do it for the reasons enumerated above.

I have never heard any change in tone resulting from slotting the bridge, although I’ve read anecdotal evidence from others that they heard improvements when they slotted their bridges. I have to say that I’ve never heard a tonal change either from changing pin material, so maybe I have tin ears? ;-)