I'd like to add that even wet feathers still steer well. I've gone as far as to soak feather fletched arrows in water before shooting fixed blade heads just to see how they worked. They worked just fine.
I agree. I think the "wet feather" argument is an old wives tale. If I hunt in the rain, I'm usually under a tree umbrella. In such weather, though, I limit my shots to "slam-dunks".
I also agree that the advantages far outweigh the negatives (from any bow).