I'm looking primarily to use the tablet functionality for note taking...
Stop right there. I will tell you that you absolutely
need a tablet with an active digitizer for your intended purposes. Got my wife a Thinkpad X230T (convertible tablet + digitizer) last xmas. The Vaio Duo has a higher resolution screen and is lighter, but the X230T was my pick for the better keyboard, more rugged build, more versatility (we use it in 'tent' mode occasionally), more expandability (added a 128 GB mSATA SSD to go with our 500 GB HDD and added an extra 8 GB of RAM for 12 GB), docking capabilities (we got a docking station for cheap) and not least importantly, has a slot to store the stylus on the body so it doesn't get lost.
EDIT: Also, aside from not having a slot to store the stylus for the Vaio Duo, it is also retarded in that the pen is battery-powered, whereas the thinkpad wirelessly powers its stylus from the screen.
Wind, Sand and Stars.