OVER THE YEARS  more then one 13th s9  did better then a 14th s9

I have had about  1000  bitmain units from s1 to s15  and they can vary spec a lot.

If you are buying  more then 5 pieces.  I suggest not over spending on the highest specced  ones.

Yeah if they gave you a day in the factory to cherry pick  the 5 best why not.  But I have seen higher ranked not that good.

I had 1 s7 that was unreal  it clocked  like 50mhz better then any of my others and it was super good on power like 235 watts a th  which was super good for that unit.  It also never tossed hw's 100 days at a time without one.