I have both "K" an "N" frame S&W's with Red Dots. They are a SUPERIOR set up for target shooting. Here is a 16-4 with Bushnell Red Dot:
Here is a 625-8 JM Special:
The 625-8 has a Weigand base. They are super strong and well built wihtout being "clunky". I can recommend them without reservation. On the late S&W frames, you just remove the rear sight and use the already drilled and tapped holes. Piece of cake!
Dale53