I'm not sure that I can taste the difference since I've gone to pure 02 but what I can tell you is that I'm now getting krausen in the blow-off tube, faster starts and my final gravity is lower than it used to be on the same recipe. That's coming from an aquarium pump and airstone. So I'm pretty sure the yeast are loving it. The best thing about it for me is that I get my batch aerated in about a minute whereas I used to let the aquarium pump go for 20min or more. So the pure O2 system is easier and faster for me. So both me and the yeast are happy as can be about switching to pure O2.