Gleukos is made (or at least they have their corporate HQ) right here in Portland, OR, so it's pretty readily available.

I've tried it, and I like it for medium-distance rides. Note that "medium" is relative. Say - 4 to 8 hours. I've not tried it beyond that, no particular reason why not, though the sodium content is kinda low for me without added electrolytes.

It's not that sweet (dextrose/glucose is about 1/2 as sweet-tasting as sucrose/table sugar), and it is light-tasting, which helps fight flavor fatigue.

Everyone - including Gleukos - wants to show you a fascinating chart showing how much longer a single feeding of their super-special carbohydrate stays in your system than someone else's...which is great information if you intend to drink it once, then drive yourself until you bonk. Thankfully, that's not how most people approach cycling nutrition. If you keep on drinking ANY carb/electrolyte solution steadily over time, it will maintain your blood sugar without a "crash". The key is finding one that you're willing and able to drink for a longer period of time. For some of us, that might be Gleukos.