Kayak is great because it lets you search multi-tickets for both price and schedule at the same time and often showing you the lowest cost option...something Delta.com is not able to do.

And a big to the Delta tech guys who are saying they know nothing wrong with it. All they have to do is spend a couple hours doing complicated mock searches and they will get all kinds of errors and screwy returns with crazy layovers. How can they not know that?