Samsung Galaxy Note 3 has most of the latest stuffs from Samsung. Galaxy S4 will get some of the features later. But you can try them now like S-Note, SnameCard, My Magazine, Scrapbook and Action Memo if you have rooted Galaxy S4 (GT-I9500 & GT-I9505). More applications were added too like Screenwrite / Flash Annotate, Galaxy Finder, One Hand Feature… More to come I believe.
Play around with these apps (link) first while waiting for the next Galaxy S5. Or you are going to skip Galaxy devices due to KNOX warranty issue?