I had a bent mirror getting in the way of the clutch lever while on my trip last summer. In the dark, on the porch of the cabin I was staying in, I accidentally took the bar ends completely apart. After an hour of swearing and fishing with wire to get all the parts out, I reassembled the bar ends and reinstalled everything. Since then, the handlebar seems to vibrate more. THis makes me think of two things. One, is the placement of the weight more impactive than the addition of weight. Or two,(also suggested by my local dealer as a possibility) is the weight just not as tight as it needs to be, causing it to vibrate more. As these bikes are hand built/assembled, the chances of the stock bar ends just not being tight enough is a possibility. So that may be a place to look at first. I don't know how hard they are supposed to be torqued to, but before I start adding weight or modifying the handlebars; I will start there.
Just my experiance with it so far.....