Got a 30 two winters ago. The Vexilar guy at Scheels ice fest couldn't believe it when I told him I hate it compared to my Humminbird Ice 55 that went down. After he tried to debunk all my complaints his answer was to get the new upgraded 35 or whatever it is, i asked him what he would give me to trade up, no dice. I have most of my problems when I hole hop, have to power cycle sometimes between holes, really sucks when I finally get my settings the way I want them and loose them if I have it in the wrong mode. I'm a freaking technology guy and it's almost too complicated for me
Basically if you got an 18 that works good for you then stick it out until you can't fix it.