I personally didn't like the Puppia harness. The problem is, Mocha's neck is very tiny, so the neck hole would fit over his head nicely, but then be too loose around his neck. But If I had gone with a smaller size, the neck hole wouldn't have been able to fit around his head at all.
The harness was easy to put on him, but it was a pain to take off. The neck hole didn't slide
off of his neck as easily as it slid on. So while I was trying to take it off, Mocha would jerk his head/neck around to get his head out of the harness. I didn't like this since I didn't want him to be putting any strain on his tiny little neck. Another problem was, Mocha would often manage to stick one of his feet up through the neck hole.
I wouldn't recommend this harness if your dog's neck is much smaller than his head. For breeds like Pugs or Bostons, who have larger necks, I think this harness might work well though.
The harness that I recommend to everybody is the Buddy Belt. It's super easy (and takes about 2 seconds) to put on and take off. It's the ONLY harness that Mocha doesn't try to escape out of. I really think that he doesn't even feel like he's wearing one! They're also very sturdy and offer a lot of support in the chest area. Another plus is that Mocha also doesn't have a matting problem with this harness. There's been on a thread on here about Buddy Belts and EVERYONE gives it rave reviews (and for good reason!)