I carried the SIG P-226 (in both 9mm and .40 cal) for about 18 years. Loved the gun. The ammo, well, that was a different story.
As for the gun. I never had a single malfunction firing 1,000 upon 1,000 of rounds through them. Even when not that clean (shame on me), weapon worked every time.
We started with sub-sonic 9mm ammo which was TERRIBLE. We had 14 shooting with the crap ammo they issued us ('94 – '98). 13 of 14 threats continued their attacks AFTER being shot. Put your life or others life in faith that this will save you.
We "up gunned" to the .40 cal, same gun frame, but much better ammo. Dropped the threat every time. Carried the SIG 226 (.40 cal) for next 14 years. Just a great gun.
We then switched to the Smith and Wesson M&P in .45 cal. I didn't want to like this gun, I'm a SIG guy. Another great gun with very good ammo. No complaints, never a problem with it. Just like the alcoholic beverage, Colt .45 Malt Liquor, it works everytime.
My biggest problem with the 9mm was the ammo. 9mm ammo at the time just didn't have the "knock 'em on their ass" impact that the .40 and .45 did. There have been amazing advances in ballistics over the last decade and there are some very good 9mm rounds available now.
As for Glock, never carried one, but have shot many. I like them a great deal, only used them on the range, so limited exposure. My buddy has a Glock in .45 and I can drive nails with it at 25 feet. Good shooter.
And I don't think they are ugly, just a bit different.