1. The Sig is a better "natural pointer" for me than the Glock. That however is a purely personal idiosyncrasy. Everybody's different. The only way to determine this for yourself is to shoot 'em both.
2. The little 26 doesn't have the squirrely decocking lever that the big Glocks have. It's double action all the time. So that's one less thing to worry about. Of course, you'll have to check the trigger pull. On the old Smith revolvers, for example, or my .455 Webley, DA is such a hard pull that it will swing your sight picture out of line.
3. I'm not a big fan of 9mm (always carried .45 except that in very hot summer weather I used to carry a .380 Walther PPK concealed, better something, even "9mm short", than nothing) so I have never inspected or tried out the 26. I would definitely "try before you buy" because this is a tiny pistol, so small you can't get your little finger on the grip, and I imagine the recoil is going to be significant (the recoil on my PPK is WORSE than the recoil from my Colt Lightweight Officer's Model).
Here's a review of the pistol from a lady:
Glock 26: A Lady's Point of View
She seems to indicate qualified approval, but note the difficulties with stovepipes and the magazine release. Neither of those is a good thing!
This wasn't directed at me, but I've got a Sig P245 and thought I would comment on it. The grip is a little too short and the trigger doesn't seem as nice as the other Sig models.
Unless you are set on a .45 caliber pistol, I would recommend either a Sig 229 or Sig 239 for carry.
Both come in .40 S&W, 9mm, or 357 Sig. The 229 is the larger of the two, but is the same length as the 245. The grip is just a little longer. The 239 is shorter than the 229, and a little easier to conceal since it has a single-stack magazine. The 229 holds 12+1 rounds; the 239 holds 7+1 (8+1 in the 9mm package).