I will try the update. as of 14.5hrs operation for both units (Unit 1 has a v1 board and the v2 replacement board, unit 2 is v2) shows:
stat unit 1 unit 2
GH/s avg 199 204
rejected 218 13
HW 68,500 10,800
DiffR 28,000 1,700
the rest of the stats were similar enough to be omitted. It seems fairly clear from the results at 14.5hrs of operation that there is roughly a 5GH/s difference in the units, probably a result of the different firmware. Temps on unit 2 are 49/50 while unit 1 is 51/54 - I will update the firmware shortly and may try pushing unit 2 to 425MHz
I updated the firmware, and there is no change to the hardware error rate. (Bitmain, is there a way to see which board or chip(s) are producing errors?)
stat unit 1 unit 2
GH/s avg 200 204
rejected 7 8
HW 23,500 3,800
DiffR 896 1,024
also, i tried the 425Mhz code, and hashrate seemed to drop to around 187GH with more errors, so i guess temperature is a factor