SUMMARY:Chill-Its 6700 provides stellar cooling but feels slimy to the fingertip, albeit not to your neck. Another reviewer suggested hydrating less for less slime but presumably less cooling too. Highly recommended, especially if you are going to be in such hot, sweaty circumstances that you are going to want to shower afterwards anyway. More comfortable than the standard tubular neck wrap too. Dropping 1 star due to the slime factor but will update if less hydration makes a significant difference.Huachnet provides moderate cooling and is useful when you are just a little hot or if you have access to water so that you can rewet it. It is colder when wet; cool, clean and dry to the touch after 1 hour of hanging in my laundry room. It contains a good amount of polymer crystals.Chill-Its 6700CT felt like a stiff wet towel and did not impress. I would pass.(I've attached 2 photos so you can see the relative sizes -- the red is the 6700 and blue is the Huachnet. Sorry they are upside down but I don't have time to fix.)DETAILS:I already have 3 cooling neck wraps filled with crystals, bought many years ago. 2 of them are in a beautiful pattern and have a wooden bead that I can slide up and down to quickly tighten/loosen the wrap; I would have loved to buy more of these but I don't know where I bought them and cannot find them any longer. The 3rd one, without the bead, did not have as many crystals in it, doesn't plump up much, and runs out of cooling energy quite fast. I decided I should buy a replacement and, seeing as experience had already shown that not all neck wraps are created equal, decided I'd better try to find one with ample crystals.After reading many reviews, I decided to buy "Ergodyne Chill-Its 6700 Evaporative Polymer Cooling Bandana - Tie Closure" because a reviewer explicitly said it had more crystals than most; "Huachnet Cooling Sports Scarf Neck Wrap Headband Ice Scarf Reusable Ice Bandana wristband" because it was pretty; and "Ergodyne Chill-Its 6700CT Evaporative Cooling Bandana - Tie Closure" because I wondered if a different technology might work better.The Chill-Its 6700 and the Huachnet both contained polymer crystals and I put them in a bowl full of cool water for an hour (which is much longer than in the directions but I was busy and got distracted). After an hour, they were both very plump. At first, the Chill-Its seemed much plumper but I realized the gel had not spread out lengthwise; after I squished it out to fill the neck wrap evenly, the Chill-It ended up flatter and wider than the Huachnet. The dimensions of the gel section were Chill-It 16" x 1.75" x 0.5" and Huachnet 15" x 1.25" x 1". The Chill-Its gel was homogenous and the Huachnet gel felt like individual orbs, but I didn't notice any difference when I was actually wearing them later. I thoroughly wetted the Chill-Its 6700CT (15.5" x 2" x 0.25") and then hung all 3 neck wraps up in my laundry room.After 1 hour, I checked on the 3 neck wraps. The 6700 was extremely wet with a surface slime, the Huachnet was dry to the touch but still plump and cool, and the 6700CT felt like a wet towel. I checked every hour for about 6 hours and they stayed like that. Each time I touched the slimy 6700 with a fingertip, I was grossed out by the slime and had to wipe my finger on a paper towel. After 6 hours, I decided to put them on. I actually couldn't bring myself to put on the 6700 because I was grossed out by the slime so I started with the Huachnet.HUACHNET: Dry to the touch, it was easy to put on and provided a moderate cooling. The Huachnet is very similar to the neck wraps I already own. Experience tells me that on a hot day, this will become warm from the heat of your neck fairly quickly but you can take it off and let the heat of your neck dissipate and then it will provide coolness again. If you don't take it off, it becomes a warm annoying thing around your neck. It felt like a heavy tube around my neck which was pretty much what I expected.6700CT: This felt like a wet towel when I touched it and it felt like a wet towel around my neck. Not impressive. I didn't think it would have a very long cooling effect.6700: Finally, I wiped the 6700 with a paper towel to try to get some of the slime off (didn't help) and then gritted my teeth and put it on. It was ICY! And my neck didn't care about the sliminess at all. I kept it on for awhile and the 6700 cooled me down and remained cold the entire time. It was flatter than the Huachnet and I think that the increased surface area helped with the cooling effect and it definitely felt more comfortable (no tube effect) around my neck. When I took it off, my neck was slimy and I wiped off with a wet paper towel. Note that the reviewer who said that the 6700 had more crystals than average also warned of the slime and said the effect would be reduced by not overhydrating the crystals; if I soak it for a shorter amount of time, it seems likely that I won't have so much slime.