They only refunded for the lack of hashrate not for the lack of efficiency. One of the main selling points of the miner was the energy efficiency, people should be compensated for this as well. Doubled Burned! They bumped the specs up during the group buy even further than original to continue to drum up sales and were pretty cocky about it. If you are happy with this GB you would do well in an abusive relationship.
Better than a BFL relationship.
Better than a KNC relationship.
Better than a Technobit relationship.
Better than an AMT relationship.
Better than a Black Arrow relationship.
Better than a Bitmine relationship.
Better than an Avalon relationship.
Better than pretty much all the others.
As a Bitmain customer as well shipping was slower the machines had issues particularly the cards came loose in shipping and lost a PSU in first 2 months.
Not heard as many complaints about SPTech machines as Bitmain. But they are on par in my book where SPtech has the edge is the miner and the chip quality. Where Bitmain wins is getting units out to customers in larger quantities however they are mining them hard as in "stock" means you get what you get. Let us be honest about that at least. Every good company shipping today has issues.
The only abusive thing in the GB to me was the lack of a proper shipping date window.
As for the loss of efficiency... is it still efficient enough? Yes I think it is.
As for the loss of 6th/s back to 4.5 Th/s was that bad? Sure was but they admitted to the problem as soon as it was discovered and compensated us beyond the actually GB purchase numbers... which I think was a trade off. What is the overall loss for lifetime on the efficiency loss? Anyone calculated it?
Do I as a GB customer feel abused? No not really. Am I extremely happy? No not really. Would it stop me buying again if the price was right no not at all given the alternatives Bitmain or SPTech are both reliable sellers.
There are levels of professionalism and SPTech are doing better than all the others at this point. They are building the best miners at price points that have literally forced the entire market to lower their prices. Now does that mean they are perfect? No but you know what I would rather deal with an "abusive" company like this one vs most if not all the others.
My units arrived in August as promised. I was calculating arrival between August 20th - 25th it shipped on the 27th and arrived on the 28th. Technically not late. When I ordered from Bitmain... shipping delays took an extra day possibly 2 given it had to be shipped cross country by truck instead of being shipped to a local airport where pick up was easier, in comparison to the SP30s being 24 hours basically factory to door to mining. Again crunchy with the smooth. Bottomline I got what I paid for in reasonable time at the price point I was happy with. It could have been better but I am not going to grumble too much given that this is all a pretty big risk to even order in May for August delivery. NEVER PREORDER is the mantra. If the BTC price had remained over 600 and more difficulty didn't hurdy gurdy up the way it did then I would have been much happier. Neither is SPTechs fault. You take a chance every time you lay out coin on miners clearly you are in better hands dealing with SPTech than most. I would buy again if I could find the same discounts I received last time.