After now owning a 1911 (45ACP), I can def tell that my follow up shots (rapid fire) is slightly faster with a 9mm than a 45acp.  This is due to the recoil and getting the sights back on target. But the operating systems are 2 different ones, so IDK if that's also a factor, VP9 vs. M45A1.  I guess to see a closer comparison, I would have to shoot a M45A1 and another 1911 in 9mm. Or a VP9 and another striker fired 45 as the HK45 is hammer fired.  I also have much more time on the VP9 than the 1911, so that's a factor as well.

But of the 2, I am more accurate with the 1911.

hard to beat a 1911 trigger