I've been around the block on autopistols more than once. Started with war surplus 1911A1s owned by my father and uncles, went through the wundernine trend, have dabbled heavily with all manner of "tactical plastic" and have come full circle to the 1911A1. I actually have called them "1911A1 patterned pistols," as they come in so many flavors riffing off of the original design.
From the OP:
1. The 1911 as it is commonly viewed today is NOT the same 1911 that John Browning designed. In short, I do not buy this whole "100 years of history" nonsense. Now, you can argue that the evolution of the 1911 has resulted in an improvement over the original design, and depending on the specific thing your talking about, I can buy that. However, a Nighthawk Custom 1911 (for example) is about as similar to a "real" 1911 as an F150 is to a Model T.
I view this "point" as a very minor one. Any 1911A1 patterned pistol that is built well benefits from nearly a century of trial and error and debugging. Some deviations, like Kimber's recent external extractor fiasco, see the market calling the deviance to an end.
2. Going with that argument, there are plenty of pistols that have enough years behind them to be proven, tested designs. The CZ-75 immediately comes to mind. Rugers P-series. Sig 220. The Beretta 92 (M9). Glocks. These are just the ones that I can think of off the top of my head, but each of them has been around at least 20 years now, and if that isn't enough time to figure out that they work, I don't know what is.
But which would you rather have, a Beretta 92 or a Taurus "copy?" A CZ-75B or a Tanfoglio clone? Many 1911A1 fans will not buy a substandard example no matter who made it, and people studied in the nuances of the design very rarely wind up with lemons.
3. Custom shop pistols are nice. No doubt about it, a Wilson or a Baer is a great thing. However, from a value standpoint, they don't add up. Why spend $2500.00 on something when you can spend a third that on a different gun that will work just as well, be just as accurate, and will very likely have most, if not all, the same attributes that made 1911's popular to begin with (grip angle, cocked and locked carry). For the shortcomings (factory triggers being a good example), a gunsmith can work out the kinks and you will still be money ahead. Pride of ownership is an acceptable argument, and I am certainly not telling anyone how to spend their money. Still, from just a basic economic point of view, most custom pistols are over-priced to one degree or another.
As noted earlier in the thread custom level cash need not be spent to get a perfectly operating 1911A1 pattern pistol with a trigger that no other design even begins to touch as far as speed and ease of putting lead on target fast. Any other pistol using a hinged triggering system has lost before it starts.
4. Sights. Again, taking custom pistols out of the equation, most modern pistols are better than the 1911 on several fronts, with decent sights being the most major factor I can think of. Custom guns obviously negate this argument. But, going off the original design, the sights, the fit and finish, the trigger, and out of box accuracy are all sub-par compared with most pistols today.
Another non-factor. Stakings and dovetails have been available on even plain vanilla 1911A1 pattern pistols for decades now. Almost everyone's sights on any $400.00+ duty pistol beats the ever living hell out of Glock's standard plastic sights.
5. Grip angle. I mentioned it above, but I think that we can agree that there are plenty of pistols available today that have the same grip angle as the 1911.
Grip angle yes, flatness and adaptability to different hand sizes through a combination of being able to customize the grip safety, the mainspring housing, the grips, and the trigger reach? Not so much.
6. Capacity and caliber. I will not say that the 1911's capacity is an issue. If your comfortable with it, then what do I care? My carry pistol is a 5-shot revolver, so I obviously am not going to argue that 7 rounds isn't enough. What I will say is that from a logical standpoint, more rounds are better, at least in my opinion. The first one may do the job, but it just makes sense to me that having 14 more tries is superior to 6 more tries. There is a limit, in my mind, as to the usefulness of hi-cap mags. I think that those 50 round .45 mags are kind of dumb, and I think they throw things off. A 14 round mag seems about right. As far as caliber goes, I am a big believer in the .45acp round. Some of the pistols I mentioned above are not .45's, and that is not in their favor in my view. Then again, I enjoy shooting 9mm, and I own several. In the end, I guess I am saying that caliber aside, those pistols are as good if not superior to the 1911. If you want to factor in caliber, then that is only true of some of them.
More rounds are not better if they compromise carrying and shooting factors. I'd rather have the single stack 1911A1 than all of the double column pigs I have had to try and conceal over the years. The magazines are correspondingly thinner too.
The only other caliber worthy of being put into a 1911A1 frame is a full house 10mm. Sure the 9mm and the .38 Super have been chambered as well, but those aren't all that and a bag of chips with the exception of newer "shrink wrapped" 1911A1 pattern pistols built around the dimensions of the 9mm.
7. Accessories. There are tons of holsters, mags, lights, grips and other assorted doodads around for pistols that are not 1911's. This is not necessarily always true, and if you don't believe me, try tacticalizing your .22 rifle that isn't a 10-22. It's hard to do. In the case of the 1911 and it's competitors, there is no shortage of customization opportunities.
Go ahead and name one other pistol out there wherein EVERY part on it can be custom specified. From the frame, to the slide, to the barrel, to the small parts, every piece of a 1911A1 has a stable of competitors for your parts business. I have a Series 70 Colt Government that is my SHTF pistol because every part on it can be commonly replaced or successfully cannibalized from most other 1911A1 patterned pistols, without tools, and in most cases with no individual fitting required. Even when presented with a Kimber, I can frankengraft about 80+% of its parts into the Colt. With other Series 70s type pistols, such as Springfield Armory models, that percentage jumps to just about everything but the firing pin and the barrel.
8. Accuracy. Even including custom guns, there are plenty of 1911 competitors around that can equal or exceed the accuracy of the average 1911. That is not even up for argument, in my opinion.
This forum is replete with tales from wondergun shooters who have had eye-opening range sessions with the 1911A1 and an open mind. It is not that 1911A1 pattern pistols are necessarily more accurate, they are just on average easier to shoot well and fast.
To conclude, I will say that the 1911 is a good gun, and if you want one, then go for it. I like mine just fine, and I have no plans to get rid of it. I will say that I no longer believe (if I ever did) that it is the finest pistol ever made. For it's day, yes. Hands down, the 1911 was the best combat pistol in the world from it's conception up until about 1975 or so. No argument that it is still a great choice as a combat pistol. I am just simply saying that I don't buy that it is the BEST choice anymore. It very well may be that it is the best choice for you, but don't try to convince me that it is the the equivalent of the holy grail, because I just don't think thats true anymore.
Someone will have to show me the weapon that has supplanted it as the best. People who shoot for keeps tend to have 1911A1s when they could clearly buy any "better" pistol.
PS: I have yet to see a Glock, an HK, a Walther, or an XD, that has been involved in serious extended combat. Breathless tales of performance in lab tests fails to impress. The SIG 226, 228, and the Beretta M9 get a pass as they have actually "been there and done that" with armies that actually fight.
In fact, save for the FMJ 9mm rounds they would be saddled with, I'd be perfectly comfortable with a SIG or a Beretta on my hip. I wouldn't be able to detail strip them without several punches and perhaps a plastic bag handy for inadvertant loss of annoyingly small parts, but I'd trust them to operate.
Just as I would trust 1911A1 pattern pistols I have personally wrung out.