I've owned both. They are both at heart military or law enforcement weapons. It is pointless to insist on either one for just anybody. Both are well designed and built for the purpose. The intelligent choice will be made by comparing the grips; the trigger reach, weight, and feel; the sights; thumb safety vs decocker; and if at all possible, test firing.
My hand is about size 8. It felt a little more at home on the 226 grip, but the 92 was easy enough for two-handed shooting. Same for the trigger reach. The perceived DA trigger pull seemed heavier on the Beretta, not by much. Now the slide mounted safety on the 92 was definitely out of my thumb's reach, compared to the SIG decocker. There is little to gain by arguing one over the other, because individual styles vary. Comparing accuracy is also a moot point, it will be up to the shooter not the gun. Declaring the M9 a paperweight is civilian bravado, not liable to convince anyone. A typical decocker may feel cheap compared to a crisp thumb safety, but so do many moving parts in military weapons where function rules over form.