My experience with frequent smoking of "ISOM: cigars ended in 2019 (I have one or two left) when I departed Costa Rica.
This is my own opinion (and input from one of my former guests, who was a highly experienced "premium" cigar smoker*).
They are produced under a communist regime where there is no incentive to excel. None. A highly skilled surgeon is paid the same as a cigar roller (officially). Cigars are an artificially controlled foreign exchange asset for the government (hence the government monopoly). Prestige brands like [redacted] (created for Fidel) at the upper end have more quality control.
However, ISOM cigars are valued by many purely based on their unobtainability and inflated cost. Many Nicaraguan and Honduran puros are their match, but don't have their cachet. [Redacted], for example (though [Redacted] controls their market and distribution to keep prices up too).
I used to smoke a "store brand" Nicaraguan puro ([Redacted but not available outside CR]) sold by the only real B&M cigar store in San Jose**. My guest, who had a walk-in humidor full of high end, highly rated (by [Redacted magazine] and others) cigars (ISOM and others) took multiple bundles back to the US. Why? Quality and consistency.
ISOM cigars are good cigars, but they aren't the Holy Grail. I've had verified real ISOMs that wouldn't draw.
*He used to buy out whole limited edition runs at the big events.
** A certified [Redacted] retailer. The [Redacted] in San Jose didn't want to deal with retail.