Reddit user dieklobrille compared the speed of the current Xbox One UI, with the upcoming ‘New Xbox One Experience’ update, and the results seem to be quite impressive. According to dieklobrillethe tests were performed while in the main menu of FIFA 16, after a cold boot of the console.
A graph has been uploaded to IMGUR to show the results of the comparisons. If the comparisons are to be believed, the new Xbox One UI outperforms the UI of the PS4 on all actions. The speed increase between the old and new Xbox UI varies for each action tested.
http://wccftech.com/new-xbox-experience-speed-comparisons-50-faster-outperforming-ps4-ui/