Sotol is a completely different species from the agave plant although it is in the same family (the same family includes asparagus of all things). Sotol is generally distilled and produced in a similar fashion as mezcal but to me it has a much lighter taste. But enjoyable all the same. I have the Hacienda de Chihuahua añejo and have tried the reposado (the only brand I find in my area routinely) and find them pleasant to sip on their own merits.
In a mixed drink they typically do not come through as strongly as tequila or mezcal does to me.
Technically Sotol & Tequila are both genres of Mezcal.... drinks currently labeled as Mezcal are made from dozens of distinct species... which is why the Oaxacan producers have been working hard to get a NOM established (I don't recall the status on it.... but there has been a push to get NOMs for Espadin, Tobala & some of the other prized agaves.
If the disperse groups of distillers, growers & wild plant collectors could get organized in an ideal world they would establish at least a dozen distinct NOMs maybe more for each sufficiently differing genre of agave distill.
Even in Jalisco which is so overran by the shadow of Tequila there are dozens of micro-regional distills that are called Mezcal made from agave that is neither Blue Webber nor Espadin, and are not Smoked as in Oaxaca.
Any bottles from these micro-distillers that manage to make their way into the States? I am always willing to try something different! Other than the Sotol and the Del Maguey Tobala I believe everything I have is either Blue Webber or Espadin based spirits.
My understanding was that mezcal did have a NOM now although it included several species of agave in addition to Espadin under the same NOM. Several of my newer mezcals have a NOM on them although I have an older bottle of Los Danzantes (imported by Del Maguey and now labeled Los Nahuales apparently) that does not have a NOM or the green and white COMERCAM seal described here.
The Del Maguey Tobala I purchased recently doesn't have a NOM or COMERCAM seal on it either interestingly although I suspect it has been around for a few years. The dates on the label are older than those on the bottle of Chichicapa.
Had never paid that much attention to them before but noted that the Sombra has the same NOM (041X) as the Del Maguey Chichicapa. Del Maguey seems to have their finger on a number of mezcals.