We use them for ours, sometimes.
We got one for Tia when she was about 7 months old, took a while to work. She hated it and still does. It works like a dream with her now and we rarely use it. Tia is now 2.5 yrs, she doesn't really pull on the normal collar now, I would say less than 5% of the time on the normal collar she pulls.
Jake, 1.5 years - started using his canny collar about a year ago. He walks a lot better with the canny collar on than with a normal collar, but can still pull like a train sometimes (with the canny collar on!) especially when we are almost home.
I have to say though, we mostly don't use the canny collars. This is because my OH walks them most of the time and he prefers the harnesses. We only use the canny collars when I walk them which is not very often as I am still recovering from a bit of a back issue. The canny collars were recommended to us by a dog trainer when my back was playing up before, it means I can walk the dogs without any detriment to my back. Any pull is felt in my arm and not my lower back.
Our dogs don't like them particularly, I have to "trick" Tia by putting the lead on her flat collar first then hold her and put the canny collar on above and move the lead
She won't pull, ever, on the canny collar though which is a result for me
I think Jake's pulling will improve as he matures, like Tia's did. I think we would progress quicker with Jake if we used the canny collar all the time, but that's down to my OH's personal preference.
I think if you use it all the time you should get some good progress
Oh and the trying to get off the nose part, they always do that if I stop for more than a few seconds, Jake will also rub his face against my leg to try to get it off