Over time I've ended up with a few 18650s which the i2 would consider dead although I don't think I ever ran any of them all the way down the cliff.

When I received the D2 I reckoned I'd give the old buggers a go and lo behold, the D2 has dragged them all back among the (more or less) living!

Maybe my less-than-year-old i2 has simply grown old and weary, but the D2's superior smarts seem to make it worth the $6.21 price difference.

It'll be interesting to see if the D2 still performs a year on.