Surely they should offer a refund or the difference between B1 and B2/3?
What's the general consensus?
This is exactly what they should do.
I would be fine with accepting the difference between batch 1 and batch 3 prices, as long as they have really worked through their problems and can actually deliver well performing S7 units in the B3 timeframe.
Absolutely. I'm quite sure that according to e.g. US consumer protection laws they should be offering full refunds anyway. Nice to be based in China I guess.