>I have yet to see him mention any negatives with using all mediums.
There is one down side. But I don't find it that big of a problem. A medium with frames is about the same price and the same labor to construct as a deep with frames which holds a bit more.
If you do the work yourself you'll save that much on doctor bills for you bad back. If you have others doing the work for you, you'll save that much on workmans comp on people who hurt their back working for you.
But other than that, it's all gravy.