RE: which brand of engine is the "best"
I'm interested in hearing everything, otherwise how can knowedge increase? I have no reason to disbelieve you, but interpreting the data correctly is a key element in gaining knowledge. I'm very interested in the physical problems that you describe & I really want to know how this stuff happens with reputable company.
Maybe it is occurring in North America, where continental size & population may swallow & hide such information, especially if the batch numbers aren't too large.