I just read this section of "How To Brew" today. I was shocked to read that JP said pure O2 was NOT the way to go. From what I've read on this site, it seems like it's another one of those "primary only vs secondary" or "glass vs plastic" debates that lead to more confusion than answers. I started my research because of a vendor posting that their o2 kit was available again. Now I'm not sure what to do. Some people make it seem like it's the greatest thing to improve beer, and some say it's just not needed. I did read that pitching the right amount of yeast was more important than oxygen levels. But I just did a batch of beer that I pitched a good amount of yeast into that never made it to my desired FG. I've had minor attenuation problems in the past, and have wondered if an oxygenation system would help. It just seems like it's another one of those debates that never come to a clear conclusion.......a "do what works for you" thing.