Tamburlaine - positive or negative?

I believe that the following quotation is quite telling. Tamburlaine's ambition is exorbitant and Marlowe gives him perfect words to describe it.

"Nature, that fram'd us of our four elements
Warring within our breasts for regiment,
Doth teach us all to have aspiring minds.
Our souls, whose faculties can comprehend
The wondrous architecture of the world,
And measure every wandering planet's course,
Still climbing after knowledge infinite,
And always moving as the restless spheres,
Wills us to wear ourselves and never rest,
Until we reach the ripest fruit of all,
That perfect bliss and sole felicity,
The sweet fruition of an earthly crown."

and after a moment hubris enters the stage...
what do you think about Tamburlaine: was he a positive or negative character? We know that he fell but maybe he was positive to some extent?
What's your opinion?