I have them on my 08 which came with the bike when I purchased it last year. Interestingly, I didn't realize that they were primarily helmet locks until I started researching bar end weights a month or so ago. The dealership apparently didn't know either, even when they discovered the keys at time of purchase. As for their weight I still don't know, however I was able to contact the original owner to ask him if he still had the factory bar ends. Sadly he didn't but told me that the vibrations at certain rpm's remained unchanged which is all I needed to know. As for using them I haven't had much need yet, it is easier and faster to use an empty pannier, however, if I had know prior to our summer trip with full panniers it would have saved hauling the cable lock out of the top box to string the helmets & jackets together.
Looks like mine are from Barender.com., # BE-6. Would I buy them as an after market product ? I like the fact that they extend my bars a bit more than the stock ends. I have big hands and like the extra length but at $170 Cdn probably not.
Hope this helps.