A lot of people and I mean a lot...don't like the .40S&W caliber, because of the whole "snappiness" factor.
To me, the "snappiness" recoil is an excuse for those who can't handle a powerful and strong recoil. Bigger than a 9mm and smaller than a .45ACP...so why not get something in the middle?
Seriously folks, this is The High Road. We didn't become one of the largest active gun discussion forums thru machismo chest thumping. That isn't what we're about here.
The .40 has a more abrupt muzzle flip than my .45 ACPs (both fullsize and compact). Maybe it has to do with the much higher pressures .40s&w operates at.
No, it's because of the additional ENERGY that the .40 has. For every action, there is an equal and opposite reaction. But I like the 40 because the action it does on the bad guys.
It's both and more. Barrel length, weight distribution of the gun, grip shape, grip width, grip angle, how the gun fits the shooter, cartridge pressure, slower & faster burning powders, bullet velocity, etc contribute to both measurable recoil, and percieved recoil. We can debate it forever.
As to the G26 vs. G27 debate that truly is tough. The G27's dual captured recoil spring setup does do a good job controlling recoil, a particularly good job for such a small and light .40 S&W pistol. The G26 is a very pleasant sub-compact 9mm to shoot (even for a 1911 guy who doesn't care for Glock's steep grip angle).
The G26 will be softer shooting, cheaper to practice with, and provide quicker follow up shots.
The G27 is one a very few 40 S&W pistols that size and weight which is actually easy to control, relatively speaking. The capacity is nice to boot.
If you have a larger Glock pistol, I'd go get the baby Glock in the same caliber for mag ompatability. Otherwise I agree with shoot both and see which one you like best. Think about which one you'll have the most fun practicing with as you shoot them, because if it isn't fun to shoot you probably won't practice with it as much.