you find a flat induction stove better than a gas one with wok ring for wok cooking?

Yup - induction heats up quicker, although you have to use a heavy iron wok which sits still. It probably says more about how bad the consumer wok rings are though. If you have a commercial one you'd never switch from gas.

> although you have to use a heavy iron wok which sits still.

but you need a flat bottom for such a "wok" to sit - otherwise a round bottom wok isn't close enough to heat up evenly.