A couple of other major annoyances:

faulty mapping
The locations shown for hotels on kayak's maps are often wildly inaccurate.
I'm not sure how they get the display information so wrong since you can pull up the correct location by copying and pasting the address listed on kayak directly into google maps or another maps service.
But why should you have to do that when their software could do that for you?


clunky rates filter
Kayak uses a slide bar for inputting minimum and maximum limits on prices you are willing to entertain. For some hotels (and airline tickets), the upper end of the default rates can be well in excess of $5,000, and it's very difficult to set the slider so that you can precisely target your search to much lower rates, even when most of the available rooms or tickets are in the much-lower-rates range. They should offer an ability to type in a minimum and maximum, not just use a slider -- or to select from more than one range (say, ultra-luxury range vs. standard range).