I have a 686 and 629 with adjustable front sights. As above, if you're not shooting long range, different distances like Met Sil, won't be much use.
There is a sideways adjustable front sight for the Moving Target event in NRA Action Pistol (Bianchi Cup) that puts in the lead so you can aim at the center all the time, but it's not much use for anything else, either. Without it, you have to estimate 4 different leads each direction.