Is the recoil from a .40 cal Glock 22 really much of a difference between a 9mm G17? Spare me the ".40 sucks/is gay/is terrible" spiel for now.
Op,
To answer your question, yes, there is a difference. But, that should only be a small part in your decision making process. Depending upon your ammo selection (and especially if you reload) you can get 40 cal ammo that will recoil less in a Glock 22 than some other 9mm ammo in a Glock 17. But, all things being equal, the 17 will recoil less.
There are a lot of other things you should be considering, like the cost/availability of ammo. Remember, you buy the gun once, but you have to feed it ammo for a lifetime.
You haven’t said what you want to use the gun for? That should also factor into your decision. Competition? Home defense? Carry? How often do you plan to shoot?
What good is it if you save $150 by buying the 40cal but then have to spend an extra $150 every year on ammo? There are surely some good reasons to get a 40. If you want to shoot USPSA matches there is an advantage in some Divisions.
If you plan to shoot 50-100 rounds a year at most, get whatever you want and it won’t matter, but, if you are a beginner, on a budget, you may be better off with a Canik, or some other low cost alternative in 9mm simply because it will be cheaper to shoot, and you will enjoy it more, so you may do it more often, which will make you a better shooter.
I know a lot of shooters who started with a 40 and then switched to 9mm, or wish they had. I don’t know anyone that started with a 9mm and wished they had gotten a 40.
And, lastly, if you do get the 40, you can always spend another $120 down the road and buy a 9mm conversion barrel for it. Then you can have the best of both worlds.