frankly I lost track they have a different number for every one
and since they never compensated me for the low hashing batch 1's i received I do not buy any for myself anymore.
The last one I purchased for my self was a batch 2 that is rated for freq 575
I still feel they owe me about 150 usd in compensation or maybe 134 usd. I asked for coupons not coins,
They blew me off so I no longer buy for myself..
I also ended my mining in China over this. Frankly I don't understand why anyone not in China mines on a Chinese pool when kano.is has proven to crush the Chinese pools.
You are right about being upset about this, of course.
That said, maybe look at it from a karmic sense/perspective.
You got low hashing B1, then you got very high hashing B2 (I remember that you said they could do 625 instead of 575).
Maybe it was the universe smiling at you for B2 or maybe a friendly product manager at Bitmain- who knows?
In essence, these two purchases are balanced, don't you think? Of course, coupons would be a nice gesture.
I ordered pretty much one of each batch (stopped at 7) and my B1 performs very slightly below spec, but B5 can do 625 easily (5Th).
So, averaging gave me what one should expect-average hashing in comparison with what was expected.