I'm just getting used the differences between the Roadrunner and the Sidewinder myself. They are very similar. I feel like I'm getting more glide out of the Roadrunner, part of this I'd guess is that the HFs that I have seem to have substantially more dome than any modern Sidewinder I've found. The feel in the hand is obviously a bit different as well, but once you get past that, the flights are very similar. I have any easier time keeping the Sidewinder down and also, as I said before, it feels more precise to me. But I've changed my mind and I think that at this point, the Roadrunner, at least in Star plastic, is more stable than the Sidwinder in GStar. The two that I am throwing right now are both fresh. I'd definitely recommend trying one. I throw them both nose down on gentle hyzer angles and when I get it right, they flip up and glide for quite a while before fading out. I wouldn't say I'm putting either one out to 350 on flat ground though. I threw 320 with the Roadrunner last night and that felt pretty good. They are approximately equal in distance and it seems whichever one I get the better pull on is the one going farther. That said, I feel like as I build rapport with the Roadrunner, it will be the distance disc and the Sidewinder will be for shot shaping and wooded lines. Keep in mind, I'm throwing GStars Sidewinders. My beat up Star was actually less stable than the GStars. What weight is yours? I'm also throwing the Holly Finley Roadrunners and I felt some Barsbys in the store over the weekend and they felt a bit flatter.
Sexton Firebirds are more grippy and more mellow in flight than their Champ counterparts in the same weight, but don't get me wrong, they're still Firebirds. The plastic ages quicker as well. I use mine exclusively for forehand. I use my Champ for backhand OS utility.