I had purchased an iPad mini before leaving, to use as a computer and kindle and possibly as a journal, though I wasn't sure how easy it was going to be to journal on a tablet. So I brought both: an iPad and a paper journal with the intention of making a decision early on about my preferred journaling method.
WORTH THE WEIGHT:
The iPad! Takes a little getting used to, but not hard at all. And for less weight than a paper journal.
Paper journal in a hiker box at Neel's Gap!