If your fancy is a the power factor of full bore 45 and, at the same time, you are concerned about fast follow up shots, then the 45 gap (Glock auto pistol) is the way to go.  It’s quick for follow up shots, extremely accurate, and a breeze to reload, too.  The pic is mine with the ATS + Firefly. 

The 45 gap never did win the popularity contest with it’s nemesis, the 45 acp.  That’s because the 45 acp has always been an institution all by itself, an institution that will never be unseated by anything.  However, the 45 gap cartridge, I believe, is superior to the 45 acp, from a strictly academic point of view, for a number of reasons: 

You can achieve the same power factor with less powder, less muzzle flash and less perceived recoil than the acp.  In addition, it’s as accurate as the acp.   A 45 gap with a 165,000 power factor (USPSA major caliber) has less perceived recoil than a standard 115 grain round, fired from a Glock 17.  That is quite amazing because, to achieve that same power factor with the 115 grain 9mm, you’d have send the 115 grainer out of the muzzle at over 1,400 fps.  With just 4.3 grains of Hodgdon Titegroup powder under a Montana Gold 200 grain fmj fp, I was able to get 827 fps from my Glock 37. The recoil was so mild that I thought something was wrong, but the chrono does not lie.  With the 45 gap, you can have the same accuracy and the same power factor as the 45 acp, but with quicker follow-up shots.  Count me in as cult follower of the 45 gap.