Comparing different eras is impossible. Football is completely different now. The most obvious difference is the protection players get. Pitch conditions are better. Sports science means players are better athletes. You could say that is an argument for Maradona but modern coaches go into much more detailed tactics. The opposition would have studied every second of Maradona from every angle. Sports science would benefit Maradona but it would also mean he would be facing stronger and faster opponents.
But its all about opinions, so I'm going for Maradona, but I've always been biased since I saw him take the pish out of Scotland as a teenager in 1979.
Also Jesse Owen's best time wouldn't have got past the first round at the 2016 Olympics. But he was such a stand out you would have to think that with modern tracks, equipment and sports science would the man to beat.