it does more damage with one rep than the glaive weapon switch, but you have the option for more hyper reps with the glaive so it becomes quite situational. figure out of it you think you can kill him, if you’d rather dhc, if ammy is solo, etc
This may seem weird, but I find this combo MUCH easier to perform on the PS3 version than the 360 version since the 360 version plays a bit faster giving even less room to make the switch.