Because lithium C & D batteries are not available (at least readily available), any measurable improvement in the C & D alkalines is, in my view, a big deal.

As to AAAs & AAs, I'm fairly certain I'll be staying with the lithiums. However, as to the C & D's in my battery drawer (for several flashlights, radios & lanterns) --- I'll be looking to phase-in the Durlocks.

I'd be surprised if Eveready doesn't soon release an equivalent.