No experience with the Sig, but the G26 has been my "always" carry gun for years. It will shoot anything I feed it. Very easy to carry in multiple holsters... IWB, ankle, etc... Own a 17 for competition, a 19 for the house, and of course the 26 to carry. Been very happy with Glock.
If you decide on one, get the magazine pinky-finger grip/extension... really makes a difference. Add "skate-board" tape instead of the Hogue slip-on grip... makes the gun easier to hold/fire. The Hogue slip-on (in my opinion) makes the gun a little to fat in the grip.
The Glock 26 is one sweet handgun. My wife took mine over, and has put about 2000 rounds through it with no issues. Very concealable. I still get my hands on it very now and again.