There was a transition away from the high capacity or should I say, Standard capacity firearms back in the late 1990’s after the AWB of 1994, but it was mostly because the cost of a gun magazine might have gone up 200% or more. You could easily spend $1000 for a firearm and magazines depending on what it was. Once thing that I will that will never change is balance and speed. I think we have recently witnessed the pinnacle of the M4 Carbine accessorizing craze because now we are seeing more and more that people are wanting lighter carbines and 15 lbs AR15 variants is something that really doesn’t help you out in close quarters gun fights, speed does m ore than what optics you have in close up fighting.
When it comes to caliber and capacity, you really need to put some thought into how much weight you want in a firearm especially a handgun. I’ve shot some double stack 45acp handguns that were so heavy that taking them in and out of holster felt like I was wielding a ball and chain. Throw in spare gun magazines and the bulk and weight can quickly become extreme. The Springfield XD is a nice 45acp gun, but the balance of a 1911 or even the Sig 220 seem to handle better. And lets not forget, the reason for a handgun is to fight your way back to a rifle, so why bother trying to carry all that handgun ammo.