Well we had our clubs Oktoberfest meet the other week, at which, we selflessly sampled the eisbock that I bottled over a year ago with these caps, along with one of the couple I bottled with swing tops for comparison. For anyone not aware of this style, it is a big beer... a real big beer... one you would almost associate with sitting by the fire on a chesterfield lounge smoking a cigar discussing at which of your estates you will go hunting at tomorrow. Tasting the O2 capped one, you get the full aroma and taste, complete with what seems like infinite subtleties. Tasting the swing top, you could tell it was the same beer, but was as if your nose and tongue had big winter gloves on; you could almost pick up the delicate aromas and tastes, but ultimately they smashed and fell through your big clumsy fingers. For those of us who are picturing me with a glove over my nose, it was like I had already had 6 of these beers and was very merry, the same beer was there, but my senses are dulled and as such miss out on the finer things. Needless to say, I believe that oxidisation has definitely taken hold on the swing top sample. If I didn't already have way too many of these caps, after this tasting, I would be looking to acquire them, and put them on every beer I bottled. I still have one more swing top of this beer, I think I will bring it to next years Oktoberfest and see how much each of them have changed. Has anyone else done any long term comparisons?