The velcro ones? That RRRIP sound sends half of all dogs under the couch before you've got it on. One buyer put it plainly:
"I like that there's No Velcro, my dog freaks out with the noise of the Velcro." — Chris D.
The over-the-head ones? A wrestling match, twice a day, all winter — with a collar "that just screams no, take it off," as one chihuahua owner described the competition.
The thin nylon ones? They block nothing, warm nothing, and you still need a harness over the top — so now he's wearing two things badly instead of one thing well.
The Legionnaire is one piece: zip down the spine, snap the tab, clip the leash to the D-ring on his back. Ten seconds, even with a wiggler.