I also decided to look at the Glidden site to see how they're marketing this:
https://www.gliddenprofessional.com/product/Economy/Speed_Wall
This product should be perfectly fine for you.
The only way you're going to take more than 3 coats of anything to cover a wall is if you're going over any extreme color. In that instance, the best option for you (depending on what end color you want to achieve) is to go with an actual high hide primer. If you're going over standard neutrals and pastels, then you should be fine with 1-2 coats of this material. I still recommend that you stay away from the Flats though regardless of your color choice. With the Speedwall being formulated for all sorts of application, you're probably going to find that it's not paste-like in viscosity as you would find with Behr, but you shouldn't have any problems at all with a roller or brush. Just don't apply it too heavy. I recomment that you go with a 3/8" nap at most on a roller.
Hope this helps.