Our state police uses the Digital Ally system. They work but the officers don't like them as well as the old VHS.
I've got one user with the Patrol Witness PWLite. It seems like a solid system.
My department has a couple of the 10-8 video systems. They work, but I really don't care for them. They seem about half baked. Excellent recordings, though. Wires are really, really small. Tough to connect some wires without breaking them. Documentation seemed like it was a bit lacking.