On 5GHz especially with newer firmware like ZD 9.13, Channelfly is the clear winner. You may want to mess with the MTBC setting (I've had good luck with 200-300 minutes resulting in just one or two channel hops per day)
On 2.4GHz my feelings are really mixed. Quite honestly, the safest option has been "neither". There's some horrible devices out there, particularly internet-of-things (smart thermostats, robotic vacuums, fancy light bulbs, etc) that are 2.4GHZ-only and handle channel switches really badly. Since most clients that care about performance will likely roam to 5GHz given good coverage, I've resigned myself to manual channel selection on 2.4 even though it's not optimal.