Portable or not, an inflatable hot tub still represents a significant investment. Inexpensive models run around $300 or so, and high-end inflatable spas can cost $1000 or more. Before you get ready to spend that kind of money, you should have a pretty good idea of how often you intend on using it. Spending $900 to soak in a hot tub once a month is a poor investment.
The soft but non flimsiness of inflatable hot tubs may be a hit or miss depending on the consumer. But a lot of people who have sat in $6000+ hot tubs have actually preferred the softer feel of inflatable tubs to the concrete, plastic and other mashups of portable hot tubs. Inflatable hot tubs are soft but firm, and really provide a relaxing feel compared to portable hot tubs. This is of course based on individual tastes, so take that with a grain of salt. Inflatable hot tubs also inflate and deflate pretty quickly, so that is less time waiting around for it to reach max capacity so you can start filling it with water. But portable hot tubs don’t have this waiting period at all, and if you’re the type that is in a rush that extra time it takes to inflate can really make a difference.