Non-gunsmiths judge the quality of 1911s by how tight the slide fits the frame. Probably because they don't know much about how 1911s really function and the slide-to-frame fit could be checked easily without disassembling the gun. Over the years, this practice seemed to become a standard, though a very false standard. Even high-end 1911 manufactures began to make tight fitting slide-to-frame fits to satisfy unknowledgable buyers.
In reality, the slide, barrel, bushing, and of course the sights operate as a single unit, all locked together. The frame is nothing more than a platform to mount the slide. As such, the real accuracy issues are how well the barrel fits the lock lugs, the barrel's hood fits the breach face, and how tight the bushing fits the slide and barrel. When these parts fit snug, you will have an accurate gun.
A good example: I have a Les Baer that is very tight in all respects. It is an excellent shooter however, all it takes is a little powder crud and it starts to malfunction. I've found it has to be field stripped every 50 rounds to clean the rails and lugs. The measured vertical and horizontal play in the slide-to-frame fit is .002". My old Series 70 Colt has seen a gazillion rounds run through it. It has .020" horizontal side play and .012" vertical play in the slide-to-frame fit. It rattles like a BB in a freight car. The barrel fits the slide tight and it has a collet type bushing that also fits tight. That old Colt will shoot just as good as the Les Baer for accuracy and it never malfunctions, even after 250 rounds have been fired without cleaning.
Another characteristic unknowledgable people judge 1911s by is trigger pull. It is so easy to smooth and lighten a 1911 trigger that it's not an issue when buying a gun. If you don't have the talent to do it yourself, a compentent gunsmith can do it in a few minutes.
Another example: Last year I spotted a Randall A-231 1911 at a gun show. I asked the dealer what he wanted for it. He told me nobody had ever heard of this off-brand and besides the slide was a little loose and it had a horrible trigger pull. I took a look and found it to be in "like new" condition with the box and papers. He said he was trying to get $400 out of it. I didn't haggle a bit and smoked the cash on him. After I got the gun home, I went through it and cleaned it up. A little buffing and spring work and the trigger was a crisp 3.5 lbs. The Randall was a tack driver. I sold it a few months later for $1500.
The beauty of 1911s, aftermarket support is the best of any gun available. If you just want a shooter grade gun, don't be afraid to buy a used one. Worst case, you might have to replace a barrel and bushing to get really good accuracy. Later you can customize it with all sorts of stuff including grips, sights, beavertail grip safety, extended slide lock, thumb safety, trigger, mag release, and a host of other things.