Just wanted to add my positive experience, since forums tend to get filled with negative experiences:
I received my full kit order on Nov 5 and put it to work as soon as I could. I encountered many problems as others have described on here with boards cycling to 0, even with 2x200mm 166cfm fans moving air through. I kept rearranging boards to minimize the SPI errors from dragging other boards down, until I was left with 8 cycling boards and 1 EOL board (only 11/16 chips detected). I do believe there are still 4 buses, since the EOL board only brought down slots 6 and 7 with it when it was in 5 at the beginning. I was only getting somewhere between 200 - 300 GH/s as boards kept cycling.
My heatsinks finally arrived on Nov 6, and I put them on the back of all the regulators except the EOL board. This stabilized most of the boards, leaving only 2 cycling boards and 1 EOL board. This stabilized my hash rate to about 31-33GH/s per board. That was roughly 450GH/s with 2 boards cycling on and off and the EOL at about 22GH/s. It dropped to a bit less than 400GH/s during the day when the room temp got warm, when 2 other boards started cycling for a total of 4 cycling boards.
On Nov 8, I finally found time to put heatsinks behind all the chips except the EOL board, and this stabilized all the cycling boards. Each board was getting 33-35GH/s and I was getting a stable 530GH/s. On Nov 9, I moved it to its permanent home where the temp is 10F less than my testing area, and I have been getting a stable 580GH/s (36-38GH/s per board, 25GH/s EOL board)
I think the following quote from punin is exactly why so many are having problems in this thread in the past few days, these cards are going to be unstable unless you have adequate cooling or turn down the pot setting. I needed heatsinks at both the regulator and chips in order to get all the boards stable (some were stable with only air cooling, some needed heatsink at the regulator, and some needed heatsinks at the chips)
We have been testing the new M-boards and H-cards today and they seem to work ok, but are running quite hot with the factory pot settings. Max clock speed is 52 to avoid overloading the regulator. We are not comfortable shipping this product yet without further testing and perhaps changing the pot to lower core voltage setting. (which is really slow to do manually, so we need to ask the factory to do this).