I had a loader with a 4:1 bucket, we called it a clam shell. The bucket was heavy as hell and you needed 6 hands and 3 feet to operate it. No one ever stayed on it long enough to become an expert but I could see where it would be useful. We mostly used it for site demolition activities. When you used the lower blade for grading, it was hard to see what you were doing/going because the upper bucket was in your line of site. It was very unbalanced and made anything other than rough grading tough.
You leave the bucket closed for grading and a good operator doesn't see what the blade is doing, he feels what it's doing. I don't mean to say he can do that blind, obviously he needs to see but just looking will get you that washboard effect every time. And that's another plus, to using a loader bucket, it's easier to float and grade when you get used to it.
