G26 is a very nice little pistol. I purchased mine the year they brought them out. The gun is the only one I own that I can say I have NEVER had a single stoppage with. Add the grip extensions and it feels like a full size gun.
To me the G26 is just about ideal for a carry gun. Light, tough, reliable, no-snag, 10rd. , tritium sights, controllable, my wife can use it with ease, 17rds available with a mag swap, lots of holsters available, and roughly the same size as a .38 snub.
And yes .357 Sig is much more powerfull than the 9mm, but muzzle blast is also considerably greater in the shorter guns. I have fired my g26 side by side with a guy shooting a compact Sig Saur in .357 Sig, I could shoot faster and more accurately with a lot less blast. I doubt any persons of evil intent will be able to tell the difference between a chest full of .357 Sig or 9mm Speer Gold Dots, except with the 9mm I can put more holes, closer to CoM, and faster.