In my honest opinion when it comes to my EDC I prefer the Glock, regardless of G19 or G20. However, when it comes to shooting my reloads, I prefer the M&P 10mm.
If Gaston Glock came out with 18° grip angle along with what they have now which is 22° angle they would sell many more Glocks.
People like myself would buy them because it has a grip angle I and many others are use to.
Call it something like Glock 19 and with small number 18° beside the 19 or whatever Glock model to denote it has the 18° grip angle, or literally put 18° on the grip or frame.
Glock is probably one of the most dependable handguns made now days. Not saying that there aren't others but at the cost of a Glock its hard to beat. I bet they would sell very well.