I looked at inflatables just to test the water and see if we would even use the tub because it seemed like a cheap way of testing things out. A LOT easier to write off $300-$400 compared to $3k-$30k for a fiberglass/non-inflatable tub. Up front during the first week I researched I found the same as you...I found what I WANTED to find. That these inflatable tubs are amazing and gives you a cheaper option that lets you have a hot tub.
But once I started trying to find the cracks in the system and the downsides, those seemed to be far more prevalent compared to the "I've owned it for a year with zero issues" reviews. Notice how you've NEVER seen a review that talked about satisfaction long term like 2+ years?? These are largely disposable. Plus, because I am not starting to educate myself on real hot tubs (quality, construction, parts, companies, etc.) I can say these aren't even remotely in the same league in any capacity other than being containers that hold water.
Intex used to make a tub with jets AND bubble ring...now it's just bubbles. So essentially what you have is a blower that pushes air into a ring and then that air floats to the surface of the water. Compare that to a hot tub with actual pump(s) and jets that uses a lot more force to get water moving (instead of air) and it's enough to massage muscle/skin tissue. That's just one example.
As for brands... there's different levels of inflatable. Some are more kicked up and supported than others as far as construction and those higher end ones can go to $600-$700-ish. But for the spa-in-a-box plain inflatables, I found the best customer support, quality, and support info/videos for the Intex. Coleman seems to be decent to. Beyond that I'm convinced there's a parent company that is just using different coloring in their tub and pump housing and they are making all the off-brands.
I'm in a similar boat that you are, and despite how different these are to real hot tubs, I still might buy one just for kicks. But I have zero expectation that it'll still be functioning 2 years from now or that I'll be as satisfied compared to a real hot tub. But I'm about a month in to my hot tub education. And once you get in to the different pumps, heaters, jets, insulation, cabinets, companies, connections, customer service, etc....it's a LOT to learn and understand. I actually came one click away from ordering this hot tub. And again, still might....but it's definitely on the lowest tier of the hot tub hierarchy. So just like with an inflatable you have to 100% know exactly what you are getting and what you are sacrificing for the price. I'm fine with no waterfalls, speakers, etc. I just want a cheap tub to massage my back. We'll see what I end up with.
At this point, although I don't own one I learned pretty much everything I could learn about inflatables so feel free to ask follow ups. I'm not in the "go be poor somewhere else" camp. 😉