I follow the advice of some of the top American luthiers - John Arnold, Frank Ford (Frets.com), Howard Klemperer, and others, all of whom strongly recommend slotted bridges over slotted pins. They have plenty of evidence, all being experts on repair and maintenance of vintage instruments, as well as being builders of modern guitars, that slotted bridges with solid unslotted pins are better for bridge-plate preservation, due to their making a more mechanically sound connection between the string, bridge, and bridge-plate.

I think the fact that high-end builders such as Collings, Dana Bourgeois, SCGC, etc. slot the pin-holes and install solid pins speaks for itself.

But, as I said earlier, opinions are like arses… ;-)