My DD2 is 3 mo, and at this point, I offer a full feed (which for her is still 4 oz). Until recently, I only made a 3 oz bottle, because often, she would be so deeply asleep, she wouldn't take it. As far as the gas question goes, for me, I would rather chance gas and spit up from not burping, than have her wake up. Usually, they are so relaxed and quiet for the DF, that they don't take in the same amount of air during the feed as usual. To avoid gas problems, I usually add a few drops of mylecon to all her bottles though (Probably makes no difference).