I've seen their trucks. How would it work if I lived in Colorado? Would i have to move to Springfield?
No, there are very few restrictions on where you can live. It's mostly availability of freight so you don't have problems when it comes to home time. Prime runs all 48 states and Canada. You can take your home time anywhere you like, and they off a weeks paid vacation after a year.
BTW, don't pay attention to folks running carriers down - do your research, and make your own decisions. I ran through Prime's training program, albeit many years ago, and it worked out well for me. They have excellent facilities, don't cheap out on maintenance, and you call the shots on when it's safe to operate and when it's time to shutdown. Their CDL program is set up so you get your training on a truck that delivers freight. You'll see what you're in for from the git go, and you can walk away from it within the first week it you decide trucking isn't for you
As others have posted, you may decide to stay one year or 20 - that's up to you. The important part is to get your training and keep your MVR clean. You should talk with the recruiters of all the carriers mentioned, and see what fits you.