I know the consensus is that the different brands are different guns, but what is a Glock, really? It's a polymer pistol. Just like 1911s, they always come up with new stuff (some use the old stuff), but in the end, Glocks don't have that "old-school" feel, so people are going to want to use new stuff.
So with a 1911, you can get different brands. I don't know them all, because I'm not a 1911 fan, but those who do will tell you "oh you got this brand? no wonder you're having problems." I think its the same with poly guns. Glocks are good, but so are some of the others. Glock is my #2 choice, my #1 being the XDm. Why do I like the XDm? For me, it was the magazine capacity and the look, as well as some other minor differences (which Gen 4 corrected).
So the whole thing of Glock being perfect...it wasn't perfect and never will be. Neither will XDm. Glock was simply the best new thing of its time, and they are just making refinements while other brands are designing whole new pistols to compete. I'd say Glock is doing fine for themselves, and I may even get one down the road...but like I said - it's not my #1.