Hip boots are great for shallow wading, but seems like you always need to go deeper. Great for soft clamming etc. Only watch out for the wet a_s... All have a place...
Depends where you hunt, type of boat you hunt, etc. If you hunt a BBSB style boat, you're going to get wet very quick with only hip boots. If you hunt a bigger more upright seated style boat you might be able to get away with it. In any event, I have found myself standing in water above my hips on many occasions.
Seems like every time I wear hip boots I end up wishing I had waders instead.
Like others noted, waders keep you dry and are great even when you never get out of the boat.