Yes, they are better than the BF's. They are also more expensive. Every review I have read says they are excellent decoys, but cost is a factor. You should look at the Avery GHG's before you decide. This needs to be a personal decision, not one you can make on the opinions of others.
Regardless of your choice, I would not get rid of your BF's until you simply have too many decoys of another type. You can mix them in your set.
Regardless of your choice, I would not get rid of your BF's until you simply have too many decoys of another type. You can mix them in your set.