If you are like many 1911 shooters, you will end up owning more than one, along with extra grips and parts.
For a starter 1911, it's hard to beat the Mil-Spec, unless you are into retro stuff. If the idea of a WWII style pistol thrills you, then get the GI. It's durable,and decently accurate if you can use the sights effectively.
The big difference between the Mil-spec and the Loaded is the beavertail grip safety. The Mil-Spec won't bite, but the Loaded is still more comfortable to shoot high volumes of ammunition with. If you are a 500 round a day reloading guy, consider the Loaded. There are a lot of other differences, but when it comes to shooting the gun, that is the primary one. The dovetailed Loaded front sight makes sight swaps a snap. the ambi-safety makes shooting the pistol easier if you are a Southpaw.
The Loaded is a good pistol, no doubt, but there are other options in it's price range with similar features. If you are going to spend that amount of money, you may want to consider the other options as well. I'll list a few and why they may be options, if you don't want to consider them just skip over that part to my last paragraph.
A used Series 1 Kimber Custom (assuming you can find one for sale). This is a great gun, no FPS, and very durable. Also accurate and reliable (not that the Springers are not). Other used Kimber Series 1 pistols fall into this price strata as well. These include the Pro-Carry and occasionally others. The good thing about a used Kimber is resale value. somebody else took the new gun depreciation hit. You can sell it for as much or more than you paid for it. If the idea of that thrills you, check out
Xavier's used 1911 buying guide.
A Colt NRM 1991 is another option. Colts hold resale value well too. Often they sell used five years later for more than you paid new. This is the hidden benefit of the Colt, and the hidden problem with the Springfield. The Springfields just don't fare well at the trade-in counter, especially if you modified it. Of course this is only a problem if you sell the pistol. Be aware that many 1911 shooters do end up selling and buying and trading fairly frequently.
I have found the Smith & Wesson SW1911 to be an excellent gun, despite the external extractor. These are also in the Springfield Loaded's price range. They suffer at trade-in too, but I expect that to change over time.
If you are planning to carry the 1911, a lightweight frame does make a difference. This is where a used SW1911PD or a used Kimber Pro-Carry will make a good choice.
The bottom line is the first 1911 will likely not be your last, nor your only one. By chosing Springfield, you are getting a good gun with a reputation for customer service second to none. Chose one and get into the 1911 game. As you shoot it, you will discover what your specific needs and desires are. Then trade it off, modify it, or sell it in search of your own personal perfect 1911.