actually some Micron D9 do behave exactly this way.. binned for certain timings.. looks like OCZ binned them thoroughly

My 9200 FlexXLC were the same way optimised for 5-5-5-x or 5-5-4-x.

Guess the 9200 Reapers are as i expected doing better than 9200 FlexXLC considering they're rated the same but Reaper don't need the 8 layer PCB to do it.