they're classics and still have (obviously) iconic styling (and for those reasons I'd still love to own one), but by modern standards they're pretty poor performers. In reality, they're hot, uncomfortable, unreliable, and by modern standards, slow. A 30,000 dollar mustang GT will beat one in every possible performance test.
Like I said though, I'd still own one. Nothing quite like a Countach, in terms of looks and status and history.