I honestly think a lot of research is biased too not necessarily intentionally but if they haven’t trained with it, they don’t really know. Or even if they have, I’ve found a lot of them base the research off of the bad trainers that just zap dogs on 100 and not the ones that use them properly then claim they’re terrified and the tool is horrible. Same goes for the other side though. Thinking positive trainers are all cookies and no rules.
Anyway, Brewster LOVES his because it means we get to go somewhere fun like the marsh or a hike. He comes running over as fast as he can. He’s not scared at all. Now, granted, I rarely even hit any buttons anymore but still. Even when I did, he wasn’t scared at all. And the one I have they claim is blunted stimulation like a tens machine. He did have a cheap one that I think was hurting so I immediately got rid of that one when I realized and found a higher quality, gentler one. Mostly though I use the vibration. Even if I need to use the stim, it’s a very low level. I can’t even feel it (I’ve tried it on myself). I think it’s like 8 out of 100 some levels.