Besides the 9mm SIG 226, I was looking at the 10mm G20 Glock. Any opinions?
My opinions have changed & evolved over the years I've carried concealed handguns. At one time or another throughout the years I've carried .22, .25, .380, 9mm, .38 Spl, .357 Mag, .40 S&W, .41 Mag, .44 Spl, .44 Mag, .45 ACP & .45 Colt.
I generally try to avoid shilling calibers, and often even particular makes/models. If pressed by one of our folks looking for a new off-duty weapon, or a private citizen looking for a CCW, I usually try to get an understanding of his/her experience, training, skillset, comfort in carrying, anticipated needs, etc ... and then let them try out a number of different guns I own, guns kept in training or guns belonging to other instructors. Their choice has to suit
them, not mirror something I may be using at the time.
I've seen my fair share of folks choose larger guns in size & caliber than they were actually able to consistently shoot well, and I've seen them go the opposite direction, going too little for them to safely, comfortably & confidently handle them when pressed to perform demanding drills.
Everyone's got to find their happy medium
of the moment, and then be prepared to later on decide they might want to change, or at least refine, their decision.
I don't look for muzzle energy and "Magnumizing" my dedicated defensive weapons anymore, myself.
Perhaps investing some of your gun money in some local defensive handgun training might be helpful in narrowing down and refining your choice. Regardless of what you decide to choose, it's still just a handgun at the end of the day. It's still just a piece of equipment.
YOU are going to be the dominant factor in using it safely, comfortably, accurately and effectively.
Nowadays, most of the time when some earnest and enthusiastic younger shooter starts to foment some argument about make/model, caliber, ammunition selection, holster, capacity, etc ... I find it easier to simply take them down to the firing line and have them run some new-to-them, fast-paced and demanding drills, often involving more than one threat target, involving movement and threat/non-threat identification.
Quite often when the hits, proper handling & manipulation and accurate "threat identification" (shoot/no-shoot) is less than what they'd expected of themselves, I try to steer them to getting back to basics and mastering their skills ... not rely on some glitzy and gee-whiz pistol-of-the-month to offset their lack of attention to their handgunning skillset foundation.
Pick whatever you like, in whatever nice color you may like ... and get down to focusing on the arguably really critical part of it all ... YOU, and your knowledge & skillset.
Guns come and go, you know.
Best of luck to you.
