Yeah, the stretchy mesh type definitely aren't a good idea for dogs who are likely to wriggle free. Thankfully Alfie wouldn't try and the soft design of them is a bonus for sensitive skin etc as they don't rub.
Like you say, the patches won't stop everyone but I imagine they do make a lot of people stop and think. I have positive results generally when Alfie is wearing his Awareness harness, people tend to stay away more than when he is just wearing a collar.
Thankfully we're spoilt for choice for rural walks where we don't see anyone else, so we don't need to worry too much - and Alfie has very poor eyesight so I can spot other dogs before he does and recall him!
Next time I'm at a show I'll have another look at the Julius K9 ''in the flesh''