In what ways do Othello's suicide strengthen or undermine his heroism?

One could say that Othello's suicide strengthens his heroism in the sense that it's a recognition that he can no longer live with the shame of what he's done and what he's become. Once a decent, honorable man, the bravest soldier in the kingdom, the Moor of Venice has been reduced through the machinations of Iago to an insanely jealous, paranoid killer.
There is no honor left for Othello, nothing he can do or nowhere he can go to hide from his disgrace. Although he cannot now live an honorable life, he can at least die an honorable death, and so there is no option left but to die the kind of death so beloved of ancient Roman generals and statesmen.
On the other hand, Othello's suicide detracts from his heroism in that it shows his cowardice in the face of adversity. Instead of facing up to his responsibilities and facing the music for killing Desdemona, he has chosen to take the easy way out.
Suicide also deprives Othello of the opportunity to see justice done to Iago, the man who more than anyone else is responsible for his fall from grace. Perhaps Othello's still scared of Iago's demonic power, worried that his former friend and servant may have one final trick up his sleeve.
In any case, Othello's not taking any chances, and so he kills himself. All in all, it's a pretty tawdry end for someone who once earned the reputation of the bravest soldier in Venice.