My Dept. hosted a LE Carbine course last month. Most of the 20 or so students showed up with AR's (there was also a Mini-14, some sort of Ruger .40cal Carbine, and an M-1 Carbine). A Lt. from a neighboring agency showed up with a privatly purchased Hi-Point Carbine in .40cal with a Tasco propoint mounted on it. He took a little ribbing from the instructors at first, but I think he and the weapon ended up doing pretty well. No reliability problems at all. BTW I think one of those kids at Colubine High used a high point carbine.
Didn't shoot it myself so I guess you can write this off as 2nd hand BS.