Frankly, except for the traversing feature on the Blackhawk, I don't think there's ten cents worth of difference between them. The Harris "S" series has a swivel feature that I believe does the same job as the Blackhawks traversing mechanics, but Harris tends to be more expensive. I'm a Harris bipod owner, but I don't see any reason to buy the Harris if you like the Blackhawk better - go for it.
Caveat - when you're on target and having to move laterally to maintain alignment as you swivel on the bipod, there are all sorts of sources (most of them physical) that can dramatically affect your shot. Makes me wonder if the traversing idea is as good as it looks.
I have a great woman, fantastic kids, a warm place to sleep and an accurate rifle. Life is good ..............
Hunter Safety Instructor - California Hunter Safety Meritorious Service 1971 - 1972. Rifle/Pistol Marksmanship Instructor - NRA Life Member
American rifleman's triad - God, guts and guns. It built America and it'll preserve America. Abandon one and you lose them all.
As iron sharpens iron, so one man sharpens another.