The Samsung Galaxy Note 4 may be the ideal "phablet" for medical students who are often busy scribbling notes while standing. Maybe I'm from a different era, but I still rely heavily on using a pen. In fact, it still amazes me that other manufacturers are not actively incorporating an active digitizer into their devices. Doing so adds cost and some additional thickness to the overall device, but aren't people still jotting notes and scribbling on their smartphones? You shouldn't have to buy a special Bluetooth stylus pen to write accurately on your screen.
The iPhone 6 Plus is a great phablet if you don't need to "write" on the screen, but I'm still someone who relies too heavily on "inking" (to use some old tablet-PC jargon) directly, which is why I'll always be biased towards devices that offer a solid pen-based interface.