I've tried a lot of the products that are out there. Had a Bushnell for a while and it was definitely slow. It takes its reading close to the gun because it's low power, so the ball loses speed over distance. (A Jugs gun takes the reading out of the pitcher's hand.)
The glove radar isn't bad, but it's also a little slow for the same reason as the Bushnell. Very convenient if you're catching, not so much if you're not.
I also have a Pocket Radar and found it to be the best of the inexpensive devices I've tried. I've done it side-by-side with the Jugs and it's either right on or 1 mph slow. So if you're going to do it, I'd say that's the way to go.
The glove radar isn't bad, but it's also a little slow for the same reason as the Bushnell. Very convenient if you're catching, not so much if you're not.
I also have a Pocket Radar and found it to be the best of the inexpensive devices I've tried. I've done it side-by-side with the Jugs and it's either right on or 1 mph slow. So if you're going to do it, I'd say that's the way to go.