I struggled at first, as well. However, the more you use it, the easier it becomes. Players love the green-yellow-red graphics and the slo mo. I find it especially helpful for those players with poor swings as it leaves little doubt about it once they see it themselves. It's also useful for highlighting speed.
I took about 20 swings with it. I can understand the numbers and what I should be aiming for, but the path/plane graphics don't help me much because I'm not really sure what I should want to see AND how to get there. I can look at mine and look at Mike Trout's and go "well, that's not quite the same." I'm not sure how helpful that is.