It seems that even with 2.8-2.9kH per rig, there is still a big luck factor involved here. The funny thing right now is that bminerr2 now catches up bminerr1 in terms of the total amount of accepted shares (30 more shares now), although bminerr2 should be slightly slower than bminerr1 according to the reported number.

So I have to emphasize again that this is just for my own testing. It should NOT be interpreted as a general test that applies to all.