I was once where you are... I had to decide whether to select between a Springfield Milspec or a Spartan.
What attracted me to the Spartan was the completed pistol with all the nice tweaks right out of the box. Great rear sights, tweaked hammer, nice beavertail safety, parkerized finish. All of this for $ 800 plus taxes and shipping.
I ended up buying a Milspec (even if it did have the silly ILS mainspring housing). I spent another $ 100 to buy a bunch of Wilson Combat goodies since I personally prefer this brand of tweaked components. Now luckily I have a gunsmith close by who inspected my handiwork after my installation and before my shooting of the now modified .45 pistol. Just my taste, I guess. I wanted to do the work myself (that's half the fun) and select the .45 tweaked parts to fit my hand and my game.
Now that I've experienced the entire build, I would recommend the Spartan for those of you who are not familiar with tweaking the .45 1911. The Spartan comes all dressed and ready to shoot right out of the box. That's a major plus for folks who would rather shoot the pistol instead of work on them and then shoot.
Personal pride, the need to tinker and learn, the desire to customize the pistol into your own style are all factors that will weigh in favour of the Springfield Armory Milspec.
Besides, my wife shoots a Springfield 1911 9mm single stack and I wanted a 'brother' for the 9mm Springer. So now I've got a Kimber 1911 .22LR Conversion kit sitting on top of my Springfield Milspec for practice and the .45 top end slides back on for serious range work.
Buy what fits your budget and your personal tweaks.... Life is short !!