
I would say the gentle leader every time. The webbing is softer, with no hard edges, and the design icorporates a slide on the loop that tightens on the nose. This allows it to be adjusted to fit snugly, thereby preventing it being chewed when slack, so can be left on when off lead, or when you aren't looking.
With both I would always advise using a half slip collar to attach the lead to both the headcollar and collar, in case the dog manages to get out of the headcollar. With the half slip it soesn't impede the use of the head collar.
We have4 both available for sale at training class, but nearly all owners once fitted with one prefer the Gentle leader.