It would be pretty impressive, but like Boltgun said, it kind of out-throws what you'd most likely want a 9mm carbine for.
Granted, you can due relatively useful work out to 100 yards with a 9mm carbine, but that's more for how far you can push it when you have to. If you know in advance you're likely to take a shot at anything @ 100 yards, you should be grabbing something other than a CX4, and a light with longer reach should be matched with a longer round, IMO.
Since full auto is not a factor other than to collectors and LEO/Military these days, I see the pistol caliber carbines existing to fill the niche for spaces and distances where full blown rifle balistics are overkill, but you want to add on the benifits of a two hand + shoulder stock hold a rifle has over a handgun for control and accuracy.
I would mate the CX4 with something a bit smaller that works well at room distances, or perhaps "backyard" distances. (Assuming your "backyard" is average/suburban in size, and not 1000 acres)
However, as Boltgun also said, if you're just dressing up your favorite plinker with high-end accessories for fun, go for it! It's not like it's welded onto that CX4, you can allways put the m97 on something with a longer reach later if you desire.
