I have a Glock 33, and couldn't love it better. Recoil in the subcompacts is a bit much, due to the light weight of the gun. Won't hurt, mind you, but don't expect match accuracy. As a carry gun, which is what I use mine for, it's great. It rides tight and you'll never notice it's there until you want it. And the fact that it doesn't aim worth a damn is made up for by the situation. If you actually need to draw concealed, you're likely within a 7yd range or so, and have the option of just pointshooting.
Which is where this gun accels. Also, don't be afraid to pick up one or the other if you find a great deal. You can, with minimal cost and gunsmithing, rebarrel a Glock 33 to take .40 S&W. The two even use the same mags.
But do beware, as was mentioned, of the ammo cost. .357sig isn't a hugely popular caliber, hence the fact that good self defense ammo, like GoldDots or anything else runs pretty high up there. This especialy hurts when you consider that you should practice with something close to what you'll carry.