i think that using a grip that alows the disc to slip instead of rip is what non-power grips are good for. the slippage is good for clean, accurate, no flutter midrange shots.
in my opinion people should learn how to feel their wrist through the hit. it's not a matter of curing "wrist always rolls over"... it's a matter of knowing how to roll it over when you need to, or forward or under when you need to.
when throwing you should be concious of how your wrist is rolling. i think the thread in the "training assignments" section about hitting the same lines with drastically different discs will teach people how to use the wrist's behavior to their advantage.
one of my favorite throws is taking a really understable driver and getting it to hyzer the whole flight... this takes some roll under.