After 45 years of competition, practice, and hunting with well over 30,000 rounds personally through the rem 700, M16 style, and Mausers bolt rifles, and observing as many or more, I can't say that any one of these extractor designs stood out as being particularly better than the others. They all have to be kept clean, and wil give problems with excessive or poorly constructed hand loads. On the other hand, I have seen failures to feed with the push feed design regardless of the extractor type. This had more to do with the feeding process then the extractors ability to extract the cartridge or spent case. If I had to concern myself with absolute reliability of a bolt rifle design, ie close quarter dangerous game, I would choose the Mauser CRF design. IMO.