By all recent accounts, absolutely.
"Mensch (מענטש) a word that means "a person of integrity." A mensch is someone who is responsible, has a sense of right and wrong and is the sort of person other people look up to."
What makes me think Sigma's CEO is a mensch?
They Make Great Glass at a Great Price Point
Earlier this month I asked an obvious question: "When will Sigma make their fast, full-frame coverage Art lenses available in native Sony E-mount?" After all, they're making stellar optics at very attractive price points (like their 50mm f/1.4 in EF mount), and Sony is really taking off (their CEO says so, too). Then again, it takes time to shift gears and do it well.
Right there: mensch-like quality. They're pricing and delivering with integrity. Or, to put it differently: seems to me they're creating and pricing their products the way they would want to be treated if they were their own customers and employees. They probably could get Sony e-mount lenses to market faster if they subbed to a Chinese manufacturer, but thus far they've chosen not to.
More about that next.
They Turned Down a Buy-Out Offer from Canon
Sigma is an independent company with a clear vision of what they want to achieve not only for their customers, but for their employees as well. It would have made sense for Canon to acquire Sigma for a number of reasons, from getting their hands on sensor technology (an area where Canon is badly lagging behind Sony) to taking out a lower-priced competitor to Canon's bread and butter lens line. But this would have come at the likely cost of shuttering their Japanese plant and moving production to China, a move that Sigma CEO Kazuto Yamaki explicitly rejected because of its negative impact on their employees and local community.
Mensch all the way.
Watch this interview with Mr. Yamaki by Mobile 01 and draw your own conclusions.
Shout-out to Petapixel for the link.