I'm a .40 S&W fan.
I own 5 .40 S&Ws and 4 9MMs.
I carry .40 S&Ws as my SD firearm (because it's the most powerful pistol I can carry without going to a 10MM and I worry about over penetration with the 10) and have the 9MMs just in case the SHTF and for the wife to carry (she has diminished upper arm strength and the .40 is right on the verge of being to much in a compact). Also, the military has a gazillion (Scientific term for more than you can count) rounds of the 9MM and in the case of a SHTF, you are probably more apt to find 9MM ammo than anything else.
I figure if a 124 grain boolit doing 1200 fps is good, a 135 gr. boolit at 1300 fps or a 155 gr. boolit at 1200 fps, with a bigger meplat, is better.
Also, my Glock magazines hold 17 rounds of 9MM and 15 Rounds of .40 S&W. I figure the two extra rounds won't make a difference unless I get caught up in a drug or gang shootout. In that case, I always have extra magazines.
I know several LE officers and SWAT members from multiple LE agencies. The local LEs all carry .40s and the SWAT departments all carry .357 Sigs.
The .357 Sig will never equal the .357 Mag or .40 and there will never be a shortage of .40 brass.
I really like revolvers and have more of them than pistols, but 16 rounds in the .40 versus 6 in the .357 Mag with close to the same foot print is a no brainer in a big metroplex with gangs or working in the woods with packs of coyotes or wild hogs.
In my opinion, the 9MM is popular is because it is the current military round, reduced recoil for small/novice shooters, like women (not being sexist, they're usually a little bit small in stature than men) and ammo is cheaper than the other calibers. Also, I have coached a lot of novice shooters and the .40 seems too intimidating at first. Besides, every gang banger on TV shoots a 9MM rotated 90 degrees counter clockwise.
In revolvers, you have to go to the magnums (.357 and up) to get equal or high ballistics than the 9MM, with high recoil and muzzle blast.
In power, you have 9MM (124 gr. at 1,200), .357 Sig (125 gr. at 1,350), .40 S&W (135 gr. at 1,350) and .357 Mag ( 125 gr. at 1,500).
I also have two 10MM. The full size Glock is fine with full power loads in experienced hands. The compact is a hand full even for expreinced shooters!
Just my opinion.