I recently had SACS install a fully adjustable rear sight and a fiber optic front site on my Champion Lightweight Operator. They had to put a relief cut on the slide to set the rear sight so they ended up re-coating the entire slide to make sure it all matched up.
The communication with SACS was timely and complete, they did the work within the time they stated it would take and the price of the work was what they quoted. Great shop to deal with. I would not hesitate to send any of my Springers to them for custom work of any kind that they offer.