Hi, I am currently using Halti Headcollars on my two Springers (13 months and 8 months old). It has worked well on my 13 month old and he walks quite nicely when he has it on. However, my 8 month old spends most of her walk trying to pull the Halti off. What non-pull headcollars /harnessed do you use and why. Would I be better to try the Dogmatic and what are its benifits over the Halti??