Sometime around 25-30 years ago Gleanings in Bee Culture
published an article advocating the use of all-medium (6-5/8") supers. Of course, I was much younger and in better physical form then, but hefting around those 90+ lb deep supers was still an unwanted chore. I adopted the all-medium way of life.
Presently, among all my hives I am using only 3 deeps. Those are just for my pleasure (to play with, because they are different than mediums). I also have adopted small-cell because it sounded fun and purposeful. I was initially using all-wax small-cell with horizontal wires, but began using the plastic base small-cell as soon as it became available. I like it especially, because sometimes I forget and leave equipment idle too long and wax moths turn all-wax comb/foundation into empty frames and comb/plastic foundation just reverts back to plastic foundation.
I like using 3 mediums for the brood chamber(s) and mediums, as necessary, for honey supers. All the frames are interchangeable, even those in the honey supers. This can be very convenient whenever any manipulations may be necessary. Good for creating nucs too.
The small-cell plastic foundation presently is only available in full-depth size. It can be cut in half through the horizontal plane and used like this:
I have heard that "Dadant" is thinking of discontinuing supplying this product. This is making me sad :(
Here are a few more photos illustrating this idea: