Here's what Innova has to say about the Thunderbird:    

The Thunderbird comes from strong bloodlines. The stability of a TeeBird with the speed of a Valkyrie; it can be described as a seasoned Firebird with less fade. The Thunderbird is predictable in wind and a great long range placement driver. Pros will appreciate the shot shaping ability of this driver while less experienced players will find a consistent, predictable flight.

Speed: 9   Glide: 5   Turn: 0   Fade: 2