I don't know about the Glock but the SIG is threaded. My Grandson has a relatively small RF suppressor which makes the little 322 even more enjoyable to shoot. Both of us have RD sights, mine is the Romeo and his is a Holosun of some sort or another.
From what I see the prices, all things being equal, are very comparable but the SIG is optics ready and, as I stated earlier threaded, which may or may not be of any consequence to you.
I'm a huge S&W revolver fan, have been for 50+ years, but when it comes time to go shoot 22 handgun, it seems the little SIG just magically appears.
Yes, a modicum of care must be exercised when loading the magazines, but if one can't do that, perhaps they should not be around firearms to begin with.