I'm looking into Hipshot Ultralights and just got off the phone with them, so I figured I would share the information they gave me.
HB2 vs HB6C ultralight 1/2"
HB2
.205 lbs = 3.28 ounces
total weight for a 4 string = 4*3.28 = 13.2 ounces
total weight for a 5 string = 5*3.28 = 16.4 ounces
HB6C (1/2")
.105 lbs = 1.68 ounces
total weight for a 4 string = 4*1.68=6.72 ounces
total weight for a 5 string = 5*1.68=8.4 ounces
Generally looking about 1/2 lb less weight with ultralights
