My readings were from a jug and my son was considered slow at 80 mph in varsity. Several of the pitchers were drafted as well or D1 college throwing 90 +. My son's reading were from MLB camps. At 17 he was throwing 83-84 and had scouts all over him but they wanted more velocity. The craxy thing is his velocity hasn't really changed much at 22 yo even after 3 years of college.
We did have lots of sub 80 pitchers but they were not very successful as a rule. We had several that were 85+ based on MLB camps readings. I also had a jug that was used by his elite team and charted their home games. They also had several 85+ guys. Below 80 was considered very slow.