I bought it for my medium sized dog because she was getting rashes from her collar. It took a few days to get her used to it, and putting it on is a bit trickier than a collar.
It is very comfortable for the dog to wear, if put on properly. However, the adjusting mechanism is very hard to operate, and it often slips off if the dog backs up.
The hook is also prone to catching on the harness, and rips it up.
Overall, not a bad product, and certainly better made than anything else in the price range.