IMHO... anything short of an exact copy or same platform with but matching controls is just wasting your money. If your gun goes down you want something that you can pick up, it holds the same, recoil impulse is the same, etc. You are better off to save a little extra and get exactly what you have or find something used online and change parts to match yours.
You also want something that will feed the same ammo reliably... going with an open glock you will not chamber 'long' 9 major ammo as easily.
In the meantime carry a spare optic and a few other items like extractor, etc. in case something goes down on yours that you can quickly fix/rezero. Of all the times I've seen people's guns have issues (short of blowing them up) it was due to small part failure.