I totally agree, I can understand they need to go cheap so the price is reasonable ( ebay prices ) but in some areas they should pay more attention. I got full refund for this engine as I wasn't going to put up with it any longer.
I'm happy to be flexible and accommodating and even paid to get the new cam but I reached my limit and weren't willing to invest anymore time.
On the contrary to R31 my H75 works flawlessly and it's an impressive engine. I'm not expecting to last long but it works for time being at least.