I bought used guns with different sights, Ghostrings, 24/7 regular and Big Dots, and recently Truglo Fiberoptics with Tritium.
While none of these brought any real increased speed, they did not give me an allround good sight picture. The Express sights were much slower on any aimed shot, the Truglos gave me no crisp sight picture.

On Glocks I like aggressive stippling, on 1911s a good checkering job. On S&W revolvers customized stippled Hogue grips but none do a "magic" job. I still have to practice regularly or slide downhill.