The TTI one is a pain in the ass and hangs out like a sore thumb. You have to drill and tap your existing button which can be a chore. Especially trying to keep everything perpendicular on the drill press to make the hole straight. Their button isn’t relieved on the back side at all so it hangs away from the existing button. The only thing that keeps the pad a certain direction is the screw tension. There is no key slot like on the GG&G pad to prevent it from being a fidget spinner.
SD, Yes the top piece of the IWC mount is reversed which allows clearance with the Agency guard. This leaves a bit more gap between the IWC halves which looks a bit odd but it's tight and holding up well so far. I have an Arasaki mount to try as well. Work in progress.....