Not sure where else to put it, but I think the new spen technology in the works for the note 4 is already included in the S5. I was looking through the values in the arrays.xml from the secsettings.apk and found this little string:
Just an interesting find considering they hadn't even got the patent for it or even clearance to use it by the time our phone was released.
SGS 5--AT&T--STOCK NO MORE! NAKED TOUCHWIZ!
NEXUS 5--AT&T--MULTI-ROM MYSTERY MEAT