One of the client improvements in Notes 9 was the ability to search the contents of your bookmarks (and workspace?) from the Open button in the upper-left corner of the client. That was eliminated in V10 in favor of a search option in the upper-right. The option to search applications is hidden in a 'More Searches' option. This is a step backwards.
What would be REALLY cool, would be the ability to search from the upper-right and it give you options within Mail, Applications, People, etc.... sort of like when you search on an iPhone. Short of a totally consolidated search in the upper-right, please bring back search within the Open button in the upper-left.