I measure with a low 250mA drain. Agreed that at higher drains new cells will perform better. Though, these old cells will still power a Zebralight SC5 just fine. (About a 5 amp drain.) Probably not for nearly as long on max, though I haven't done that test.
In practical terms, most people will probably use their older cells for lower drain applications, or modestly powered lights. So, drain is not as relevant as you make it out. I stick with newer cells for my SC5, because it's the most demanding application. Everything else I use AA cells in, will generally use 1 amp or less, which is fine for old cells.