I throw a vast majority of my putter shots with a kc pro aviar. Upshots, short flicks, putts. But I switch over to the zone when I want to throw hard. Hyzers, longer forehands, overhand. The zone is also like a mini firebird, in that it can do a lot of tricks.
If your replacing a challenger I assume you are wanting more of a workhorse disc, the zone won't be good for that. There's too many shots that it's not that great at. It's more of a specialty disc. Kc pro aviars are nice and beefy, no risk of turning them over. but they dont have a ton of fade if want to throw straight.
Ions are pretty similar. I would say wizards are too, flightwise. I didn't like the inner rim on the wizard though. It's a straight 90 degree angle where the flight plate meets the rim. It didn't work for me for upshots, but as a putter it was great
Please, tell me more about your aces...