I just got mine yesterday. I did the update and went to the range yesterday evening and today. Yesterday was raining and today was beautiful clear weather.
I made sure have the teeing area 6 -8 feet from the unit. At that distance, I could easily move a foot either way and still get readings. I just made sure I was aiming correctly at a target in the distance. I did find that if you are too close to the unit, it doesn't seem to like that.
I found the unit to be with distances. I was verifying with range finder, as well. I have only played with the driving range, but so far it seems great.
If hitting off mats, make sure the unit is level with the mat and not below it. Also, it didn't do the best when hitting from a covered bay into the rainy driving range. It was ok, but I'd get some weird numbers on wedges.
I give it a solid A. Very user friendly and meets my expectations. I don't expect 30k trackman, but it works great for most everything I need.