from experience...
I've read that the "old skool" firebirds are different... but modern firebirds dont perform as you would like.
They throw like midrange discs when you really want/need a distance driver type performance.
I am sure that if you found an old skool firebird that had a flat top, it (probably) does perform like the predator and how most of us really want our (new) firebird to respond.
i am sure if you had the might "Arm of Thor" you could get a firebird to be amazing, but for the rest of us it really fails to meet expectations.
You can try the Banshee... It throws like an "overstable" Teebird.. Meaning, you expect it to be shorter and more controllable as its not a speed 10+ disc... and it exceeds expectations...
you can try the Predator.... My new must have disc... It throws EXACTLY how you would expect and want a firebird to throw. Basically its a valkyrie type (speed) distance driver.It throws and responds like the "bottom end" of the distance drivers.
My "Perfect" sidearmer is the wraith... BUT, its not as long as it could be... and i started a thread about it... I can say, however, for me, i can walk up to the pad and throw it, and it performs the same everytime. It doesnt really require special arm height, etc....
you can try - Xcalibur, TeeRex, Destroyer: all of these should be longer. I am currently in the "experimentation" phase. I can say that a TeeRex-x is amazing, but its too hard to find....(it's the perfect middle point between the Wraith and Teerex.... So it can handle the extra power and stay fairly straight.)