I havent read every single reply on here so what I am about to say could just be repeat. From what I did read though there is some good advice that I would like to point out. Get to a range that has rentals, rent a 1911, most new 1911's come with a flat mainspring housing, (older 1911's come with arched, now it is a preference) so any brand will do as long as you make sure that it is the size you want. If you are looking at a commander size rent it, full size government rent it, then rent a glock, really caliber is up to you noone can make that choice, but again get the size you want. If want a Compact size (19) or full size (21,17) then rent it as well.
Glocks and 1911's are two very different handling, ergonomic, fit, finish, trigger, and weight pieces of machinery. with the 1911 you will be shooting center mast and then pick up the Glock and you will shoot high. It just happens. But you want to do a side by side with them and see which one you are functioning better. You have to remember that, with practice, both of these you need to be able to operate blind, but it still needs to be natural fitting. Yes all guns fit different. Most likely when you do this comparison you are going to find out if you are Glock guiy or 1911 guy. Basically you will learn if you are going to be the guy that votes Glock or 1911 when the "which is better" thread comes up again, and it will.
From here I suggest the next day or week or whenever you get to the range again. You rent one of them. Shoot it solely cause like I said when you transition back and forth in a side by side comparison you will shoot one low most likely and on high, which will make you feel that one of them is not as acurate. Not true, just your muscle memory and brain is messing with you. But by the time you get to this stage you will most likely have one that you favor this is just reassurance and a deciding factor. Of course then go to the range the next day or whenever, I suggest you go seperate days so you are not comfortable with one while you start to shoot the other, and shoot the other gun solely.
These two guns are really the "Cornor Stones" of Auto-pistols. It seems that they are the base that most other guns of there type are compared to. i.e. Strikers (XD) are always compared to Glock, and Steel framed hammer pistols (S&W 4506), and everything in between, are always compared to 1911's. I beleive that every gun safe should have both of these guns in them, more leniency to not having to be Striker Fire type pistol (Glock) persay but a polymer duty pistol is a must(XD, FNP(non-striker but falls in the catagory), M&P). I believe being able to handle both a Glock and 1911 well, will give you an advantage to any gun you pick up. But everyone seems to lean towards one or the other in favortism.
In the end my opinion is a Glock. I have stated more than once on here my reasons why and why I think more people Closer to my age choose them as well. I got permission from my Cpt. overseas to carry a 19 with me. So I became very familiar with it. But since I have been home and able to get into the civilian side of shooting and owning my own handguns, I have worked hard to get as comfortable with my Kimber Desert Warrior. I still lean towards the Glock but have no second thoughts on walking out my door with the 1911. So I hope this helps alittle. I kinda just got into putting down my thoughts here and it got long so, sorry about that
, but I hope there info you might find useful.