I have the mini and my husband has the full size. Actually it's his second full size because the first one leaked...so does his current one. It leaks from the airholes. It isnt all the time, so at first we thought it was temperature changes or something, but last night I refilled it and by morning it was dripping down his Seigeli box. it was sitting upright, not on its side. It isnt the coils in our case, because I can put his coil in my mini and there is no issues what so ever. Mine has never leaked one singe drop and it's just swimming freely around in my purse. I just bought him a mini that I will pick up tomorrow. i pray it doesnt leak because when they dont leak, he doesnt smoke cigs.