I hope I don't have to make such a decision, but jumping rather than burning sounds better to me. I have dreamt of flying often. If I have to die, then die flying.

Sadly, so many more people died than from the terror attack of the planes hitting the buildings. The towers did not collapse because of the planes hitting them. They were designed to withstand exactly such a disaster. In the 40s a plane crashed into the Empire State building in thick fog, and the tower designers took this possibility into consideration during their design in the 60s.

In the 70s (IIRC) the lead designer discussed just such a horrible situation. A fireball of a few seconds from the burning jet fuel. Terrible death and destruction over multiple floors, but that is the extent. Hopefully one day the truth will come out.