IIRC Ziryab is a bit older, but it's true that with age comes slower calculation.
I guess age affects people differently then. My memory isn't what it used to be either. I did a lot of hard drugs in my teenage years though, so that might have something to do with it.
He and Caruana are obviously treating blitz chess as if it were a "real" game. They're trying to make high quality moves every time. It's stupid.
Lol. I can't fault Kamsky for being a purist.