If you want to watch the Rangers in GA, it will probably be good for you. I haven't had it since 2006, so some of this might have changed, but here's what you'll get.
1. You won't get any additional Fox Saturday "game of the week" games. For that matter, Fox has a monopoly on that time slot, so if the Ranger's are on another network during that time, it will be blacked out.
2. You'll get the home team feed of just about every other game. If it's on ESPN, you'll get it there, and the RSN that it's on will be blacked out. If it's the Braves on ESPN, then ESPN will be blacked out, and you will have to watch them on whatever is showing them locally.
3. There are a few non-Regional Sports Network (RSN) games shown. Cox 4 from San Diego was about it in 2006. Other than that, don't expect much that isn't on a RSN.
I've typed this very quickly, so feel free to ask any more specific questions that you have.