UberMenu is designed to be used with 3 level of menu items. Second level menu items are headers, while third level menu items align vertically beneath those headers. Sometimes users have only the need for two levels. In that case, the vertical spacing of the second level menu items seems excessive, as there are no third level menu items to pad.

Adding this CSS to your custom styles will space the second level menu items more appropriately

#megaMenu ul.megaMenu li.menu-item.ss-nav-menu-mega ul.sub-menu-1{
  padding-top:10px;
  padding-bottom:10px;  
}
#megaMenu ul.megaMenu li.menu-item.ss-nav-menu-mega ul.sub-menu li.menu-item{
  padding-top:0;  
  padding-bottom:0;
}
#megaMenu ul.megaMenu li.menu-item.ss-nav-menu-mega ul.sub-menu li.menu-item > a,
#megaMenu ul.megaMenu li.menu-item.ss-nav-menu-mega ul.sub-menu li.menu-item:hover > a,
#megaMenu ul.megaMenu li.menu-item.ss-nav-menu-mega ul.sub-menu li.menu-item > a:hover{
  border-bottom:none;
  padding-bottom:0;
  margin-bottom:0;
}