My take on my Glock 19 vs my Glock 26 .... since I often carry both at the same time.
The grip length on the 19 isn't real difficult to conceal, but the 26's shorter slide length is slightly better when sitting.
If I can only carry one ...
The 26 can use any 9MM mag, and since the 19's grip length isn't hard to conceal, I carry the 26 with a 19 mag and spacer for that extra finger grip. If I'm kayaking in cargo shorts or in a swimsuit and need less weight, I can still use the 10 or 12 capacity lighter weight mag. At home, I use a 17+2 mag. My extra carry mag is 17+2 in case I run through the 15 round 19 mag. ... Extra 33 rounders in the house and car, just in case. (Since 30 years ago I was off on the side of the road and 150 Bikers thundered by once, but they were freindly enough.)
I had night sights since 1989 ... took them all off and installed Advantage Tactical Sights ..... much better IMHO, and easy to install yourself, much much much faster sight picture.
Sure, I have a Taurus PT709, a Keltec PF9, HAD a Kahr CW40 .... they make nice Backup Guns .... if it takes 4 shots each to stop the 3 carjackers, and I only have 8 ... My 8 shot pistols are in pocket holsters when i carry them as backup guns .... but my Glocks just work without malfunctions. Plus, none of the 8 shot guns had sights that were of any use, all are sloped the wrong way so you can't rack the slde to clear a jam easily using your belt/shoe etc. The new Bersa BP9CC is supposed to have Standard replaceable sight dovetails, should be inexpensive, but it isn't on the market yet..... plus, you only get 8 shots.
A freind of mine, Officer Jeffery Dean Ginn Killed in the line of duty on July 10, 1991 and the guy who killed him were only about 6 feet from each other, both fired all shots in their pistols, no one was hit ... The guy who killed him ran to the garage grabbed a Carbine and killed Jeff while Jeff was reloading.
Shortly after that, I bought Glocks for several of my officer freinds and retired their .357 revolvers, a good move since one best freind (who was VERY resistant to not having his .357 revolver instead of a plastic toy automatic gun) is alive now because of that.