Of course it's all in what you want to see. Personally I'm not a shows guy unless stuff gets blow'd up, so there are only two shows for me at DHS. And while I can't do everything I want to do at DHS in half a day, it's also true that there's not a full day of stuff there for me. On the other hand, I think AK is a full-day park but others don't, and the difference is whether you spend time going through all the animal exhibits, those well marked and those that are not.
So I guess what the previous poster should have said is that with the addition of one or two rides, DHS would be a full day park every for those who aren't going to watch people sing.