I use a collar and a harness on Ryo. I have seen no many people with lost dogs who believe in no collar, but when a pet is lost most people who don't own pets and find a well kept dog will only look for a collar and tags before they end their search for the owner and claim a dog as their own. They don't even bother to call a vet or check with the nearest animal shelter for someone looking for a lost pet. I rather give people easy access to my phone number than not. Unless people own pets nowadays they are not really gonna know that the dog may have a microchip or tat that can be used to help reconnect a lost dog to the owner. /
So my choice is a rolled collar and a harness for walking. My dog goes for one walk a a day and is mainly indoors but i much rather be safe than sorry,
Kisses!