Just curious, how often do you ride in your boots? Have they broken in properly? Until the zip ups are fully broken in I find them to be a little loose around the ankles. Once they are, they are very snug and very very comfortable! It takes almost 2 weeks for mine to fit just right but I wear my boots all day every day. Once I went zip up I will never get laces!
Cobalts are my favorite. I've been told by every tack shop I've been into that Ariat Cobalt are the longest lasting highest quality paddock boot that's on the market. I personally can't get more then about a year or a year and a half of use out of mine but everyone says that they will last longer then anything else out there. But like I said, I'm in them ALL DAY. Riding several horses a day, walking through mud, dry sand, washing horses, etc. For the average rider they last significantly longer.