The Theory behind the
glides is no different than the public school system's common core math. Adding a bunch of big words and theories, making it sound like it's a better setup.
But on a real life setup, You're adding the fact that the velocity of air is increased, but you're leaving out the fact that the lips of the wand are no longer contacting the carpet, making it easier to push. Truth is, you're leaving more water in the carpet. I found this out with my
prochem quad wand. I clean a restaurant every 7 weeks. I first started cleaning the restraint with a slotted glide on it, and was getting ok results. After several times cleaning it, I switched over to a single lip glide, which goes on the back lip of the wand only, and noticed that the dry times were improving dramatically, which told me that since the wand is closer to the carpet with a longer opening, it's extracting more. On one job, I went with no glide on it, and the dry time was awesome.
My lesson learned, a glide is good to help, but go slower, because it's not extracting the way the glide salesman is telling you. After the wands I've used, I feel that the PMF mach glide is the best because it gives you the combination of recovery of water like a wand with no glide, yet the ease to push with a wand with a slotted glide.