For SSP, I have a Glock 35, in .40, that is convertable to a 9mm, with a KKM Precision match barrel. Although it is a little more accurate with the 9mm barrel, it shoots a lot "softer" in .40.
For ESP, I have a Para P16-40, but, have been considering having an STI, or SVI built. I've shot Matt Burkett's "cross trainer", which I liked, but, if I have one built, I think it would be in a .40, instead of 9mm, like his. The other thing, I didn't care for, on Matt's pistol, is that it has a black blade, for a front sight. I would have something of the Hi-Viz varity installed.
Although I've been using single stack for CDP, I am asking myself why I haven't been useing a double stack. They are a heck of a lot easier to hit the magwell with.
I don't shoot revolver, but, most of the top shooters seem to like the 625.