I can only speak from personal experience and the conversations I've had with acquaintances that have smoked ISOMs. And based on the above, I have had many more problems with burn/plugged/inconsistently made,i.e., soft spots, hard spots, wrapper unraveling, etc., with ISOMs than I have with other premium cigars.
That said, out of the thousands of cigars I've smoked, that include hundreds of brands, the best cigar I've EVER smoked, IMO, is an ISOM. If construction problems/quality control issues are set aside, I think some of them are unbeatable in taste/flavor. That's why I keep investing in them (hypothetically, of course).
I still have to maintain that, IMO, if the restrictions were lifted, and quality-control remains no better, in my experience, than it is now, people would opt for the quality of the legal premiums versus the inconsistency of the ISOMs.
And yes, I think that if the CAOs, Toranos, or other premium cigars were restricted in the same manner, people would be making similar efforts to obtain them. I base this on the fact that a lot of people are willing to invest substantial money, take risks of being "ripped off," and go to extrodinary efforts to obtain ISOMs, not because of their taste/flavor or because they like them (many have never tried one or have any idea of their taste), but simply because they are ISOMs, the "forbidden fruit."
Of course if people were willing to go through the same convoluted efforts to obtain CAOs and Toranos, their quality-control might very well take a nose dive, since they would be "forbidden fruit" and not have to be concerned about competing with legal ISOMs.......... 🙂