Pred, cause it's more overstable making it more predictable. I would say a Crush is about same stablity as Firebird, though a Crush is easily faster then a Pred or Firebird, I would say Preds and Firebirds are similiar in speed. Crush's speed is more like a Orc.
Pred is without a doubt more overstable, both handle wind really well. If you get on Firebird's too much they seem to act different, where a Pred doesn't seem to. I always hated how easy it seemed to be to get over Firebird's "cruising speed" making it much less overstable (just like the Crush and Drone do if you get on them). Where a Pred is like Gateway overstable, you would need a arm of a god to turn it over.
Then Predators rim only some people will like backhand, I prefer it more sidearm myself. Though my Spirit has taking it's place cause it's more overstable and faster/farther. Both Predators and Firebirds are good in the 300-330'ish range in my opinion of course depends on your arm and snap.
I however have only thrown max weight Star Firebird and Z Predator 173, Flx Predator 172g (man I miss my Flx Predator).
I like the rim of the firebird better; easier to get a good snap on it. But I am a little biased becasue the firebird I have is about 5 years old chamoion plastic, and is by far the most stable disc I have thrown to date. It has never become less stable over the years and is a good wind disc and skip disc.
you all must have some flippy fire chickens as normal champ ones are way more stable than a Z pred. The pred has more glide than a firebird. Firebird also have more high speed stability. Do people cut roll preds?
I agree with Mark that the Crush seems like the closest cross brand comparison to the feel and flight of the FB. Preds seem faster and more stable than a FB, which imo, takes some of the multipurpose uses of the FB style away. Lots of guys use the FB for overhand, hyzer and forehand short to long applications. I only used the Pred as a distance driver requiring a stronger finish or a lower line. And it didn't feel as good in my hand. To sharp a rim and it didn't sit right.
I did like it for forced S flight forehand shots though, Blair used one as his primary distance driver for that shot as was really good at it.