There are always going to be "some" trainers that don't like this or that. Where I used to train, the head halters were almost mandatory. They sold them and recommended them to everyone.
Liesje & the K9s
Nikon (GSD) U-CH SG Alta-Tollhaus Bono SchH1 KKL T1 FO PA TF-III FDCh-S CL1-R UJJ U-CA HIT TT CGC
Coke (All-American) VPC's Coca-Cola CGC, couch warmer extraordinaire
Indy (All-American) Blue Horizon's Indigo Girl, flyball star in training
Rainbow Bridge Kenya (GSD) U-CH Alta-Tollhaus-Krieger Lamb Chop CL1-R CL1-F RA HIT TDI TT CGC
vom Blauen Horizont / Blue Horizon GSDs