Dario is extremely well known and respected across all forms of Motorsport. He's been a legend of the US open wheel scene (throughout the CART/IRL schism and recombination) and although the TV coverage is more limited outside North America and Mexico far more people attend an Indy season in person than the F1 equivalent. He won several of the races I traipsed around globe to watch a decade or so back, but I didn't see him win any of his Indy 500s. But he did win the last race I went to in.....Corby.
He'd still be racing but had a career-ender at last year's Houston event when his car was propelled through a catch-fence.
He will be as good as Brundle at providing racer's insight.