It took a while, but the nice folks over at NetApp have attempted to describe what exactly Tape Smart Sizing does. I could be wrong, but I think they agree with me. I guess since I agreed with them that using single parity RAID on a VTL with 1 TB drives is dangerous (yes their Near Store VTL does exactly that...) they decided to return the favor? Perhaps...
In any event, Absolute Architect decided to pen a response which was completely complementary to my analysis. To the best of my understanding, she agrees that Tape Smart Sizing is a "confusing ... technology that won't remotely impact your life" (her words). Which pretty closely echoes my claim that it is "unnecessary and irrelevant". And I mean that literally. For most, if not all organizations, the "feature" is either unnecessary, irrelevant, or both.
Much like a square wheel bike.
Do square wheels work? Yes, if the ground is shaped like an inverted catenary. Are square wheels necessary or relevant? Not even remotely.
The analogy is perfect. Does Tape Smart sizing work? Yes. Is Tape Smart Sizing necessary or relevant? Not even remotely.
The good stuff is always in the why.