I had a twin Russell made and it's super-comfy.
http://www.gtr1000.com/graphics/mygt...n_Russell2.jpg
So far I have about 600 miles on it.
I also have a Russell on my GTR1000 and have over 20,000 miles on that one.
Have done a couple of 1000mile days solo and several 600 mile days 2-up with no problems beyond mild shoulder and right wrist ache.
If you can live with the looks and you find the stock saddle uncomfortable this is the way to go, especially if you are a fat-bast like me (6'4" & 340lbs).