Since magazines have come up, I'll throw another article on the fire:
http://how-i-did-it.org/magazines/
I found this article (and the follow up) to be a nice primer on the whole controlled feed design, and why the original specs were so, but I am NO 1911 expert. I'm sure many here have seen this write up before; if anything in there is fatally retarded, someone here will let us know.
"Feeding a cartridge into the chamber of a 1911 is not a matter of opinion; radically different magazine designs cannot all function equally well."
-the article