I'm sure with his skills he would have been a top MMA fighter if that was his profession. But since he didn't train for that, we'll never know. Part of the training is to do full contact sparring every day. That means taking blows to the head and body, every day.
Plus, at lower weight classes, there are guys that are tough enough to take everything the best striker in the world can dish out. That's why the higher weight classes are more popular, because there are guys that can knock anybody out with one punch.
I think he did some rumbling on the streets when he was younger and is pretty tough. I would not say he is so much quicker than anybody else that it would be one-sided.
The martial artists of his day and today give him a lot of respect, that's good enough for me.
It would have been nice if he took the Gracie Challenge back then too. Maybe he did, the results might be a secret.
I really enjoy seeing guys get into the ring or octagon who use his style of fighting. They look so compact and dangerous, but unfortunately, I've never seen any of those fighters be very successful.