Ubuntu’s unity really drives me crazy with its default Alt+Tab behaviour. Unity organizes terminals in groups. So when I want to switch to another terminal, first I have to choose the group, wait a while and then make a second choice to pick a proper terminal. Usually switching often between just two or three termianls the current mode is a huge time-waster.
My level or annoyance finally reached a level which pushed me to seek a solution at StackExchange. And there are indeed some solutions. First is to switch over the current group by using Alt+~. So far it works quite well for me. The new way of switching can be deactivated fully as well by using CompizConfig Settings Manager. Just follow this link.