There is a setting to disable the speed dial search, but it is hidden really well. Haven't seen a way to change it.
(You go to Settings, click outside the search box, then using the keyboard enter the old Konami code to enable "Power User mode":
up, up, down, down, left, right, left, right, b, a
Do that, and a number of hidden settings appear in the Browser page, with disabling the speed dial search in the "Start page" section near the bottom.