Ok, I don't use Eneloops and I've only owned the LD20, which is slightly different from the L2D. That said, it is my experience as well that the official runtimes seem to be reasonably close to the mark. Your estimation of 22 hrs for the L2D on the lowest setting would therefore appear to be too conservative - even judging by the data on the Light Reviews website (48+ hrs).

Either way, I can confirm that I get markedly better runtimes with my LD20 and NiMH or alkaline cells than the ones posted here: http://www.light-reviews.com/fenix_ld20/
So those estimates are either a bit on the conservative side or reflect the relatively modest capacity of the Eneloops. In any case, the very long runtime on the lowest setting on the L2D/LD20 is an important survival feature IMHO and a major selling point for the emergency preparedness minded. Not that it really has anything to do with the TK-566, it's just one more thing to keep in mind.