I understand that the regular gazelle is not overstable, but I find the cfr gazelle is a more comfortable to grip and a little bit later fading banshee for me. But I'm not a big or even a medium arm, so it might behave differently for soemone who needs a champ banshee for this slot.
Don't forget the viper also. That's kind of a weird disc though. I'd place it closer to the banshee than the whippet, but I think it fades harder than a banshee and more like a whippet. It's sort of like a whippet with more turn, so it winds up getting out further like a banshee, but taking more of a turn slightly and fade extremely hard route. It seems a little more susceptible to turning in headwind, and so I have found it to be less predictably controllable unless I throw it with a hyzer release.