Let me start by saying I own two 40s, 1 45 and 1 9mm. The 40 is the only caliber I liked enough to do twice. I cannot think of a quantifiable reason to go with any of the three, the all will work if you do your job. I prefer the 40 because I can get a sub-sonic 180 grain, a trans-sonic 165 grain or a super-sonic 155 grain projectile at any local gun store. I also like it because it comes very close to duplicating my very favorite handgun round weight for weight, the 357 magnum. If you can't find a reason to go with it fine, I did and do. As a side note, the 40 out sells the 45 in Remington brand ammo, and the 9mm is the most popular in that brand.(This was in a recent Combat handguns or Handguns magazine) so I don't think it is a flash in the pan.
As for the accuracy problem, I think it has more to do with the sharper recoil than the cartridge itself. As an example, I can shoot one-hole 10 round groups with my Glock 23 at 7yds just fine, and can do the same with a Glock 30, a USP-40, or a Ruger GP-100 all day long. That is plenty accurate for me.
[This message has been edited by Hemphill (edited December 09, 1999).]
