My dad is retired, bored, and has a Jugs gun. He takes it with him while going to ballgames just to pass time, and it keeps him occupied. He will flat tell you in a second that the Jugs gives a 2 mph faster reading than the stalker. When I tell him that it's the Stalker that scouts care about, he shrugs and tells me when they buy him one he'll use their readings then! lol.
I've had to tell him that this spring he'll have to keep that thing at home. Younggun's collegiate career begins in 3 weeks and I don't want him behind the plate gunning him. He pouted, but understood.
What NC said earlier about coaches not wanting meddling parents when they sign a kid is spot on. My son's JUCO coach said he really got a lot out of speaking to the parents, especially the dad, because it gave him an ideal of what to expect during the season.