The center tube is off center in both my iClear 16's and my iClear 30, so there's a definate way for the liquid to get out the top. No matter how many times I take them apart and put them back together, they go off center again. I still use them the most though, because I love the taste I get out of them. I have a pocket in my purse that kind of stands them all upright when not in use, so I've even been commuting with them without a problem. Only time it is a problem is when I put my device down too fast and I don't have time to make sure it's standing up, which usually only happens when my 2 yr old is trying to climb to the top of the refridgerator or something. I have an MVP 2 now, so this has been a non issue lately. That one stands up quite easily.