The
Springfield Mil-Spec is a great 1911 for a person who wants to try out the 1911 platform, and it will continue to be a gun that will perform for them long afterwards. It's only two issues are:
1. A two piece barrel. admittedly, not much of a concern, but it is a two piece barrel.
2. The ILS in the mainspring housing. Admittedly, it is easily swapped out, or you can just leave it in the off position.
The Colt ORM 1911 also has a few issues. To wit:
1. A plastic trigger. The stirrup is steel, but the rest is plastic. Not much of an issue, and it is easily swapped out.
2. A plastic mainspring housing. Again, not really an issue, and easily swapped out.
3. The Series 80 firing pin safety. Not really an issue, unless you do not want it.
Assuming both pistols are five inch Government Models, I would go with the Colt. The price is much more attractive, and you rarely see any Colt 1911 for under $500 now. You can quickly turn it over for what you paid if you change your mind. On a new Springfield, you will take a hit, and a significant one if you sell the gun. Don't forget to tack the taxes to the price tag. No taxes on the Colt.
You are correct on the thumb safety. A single sided thumb safety works best for CCW. Parkerizing, while not as durable as stainless, can work very well on a CCW gun.
Done right, it will last a long time, and you can
repark the gun on your stove. I'd go with the Colt.