They recommended the S3, and they were able to include a backrest (was worried there was enough solid area) which is awesome! It's already way better the stock seat, and it's supposed to take some time to break in (at least 500 miles - I haven't had a chance to break in yet). I'd tried to modify the original stock seat and tried two from Thailand. This one is great. But, issues (of course):
1) It lifted me up a few inches or so, which makes it a bit harder to put feet(foot) down flat (I'm 5'8")
2) Since I'm higher, the GIVI tall windscreen (which I had cut almost 2" down) was now too short! So I got a new one and will sell the cut down one.
3) Unless you move the backrest up (toward the front) at least 3", you'll be sitting WAY back (in passenger area!) I could put my feet on passenger footrests! Luckily the seat does slide forward, and I locked it in place with gaffer's (duct) tape.
It may be extravagant, but given the great orig price I've got the best motorbike on earth (
for under $5000
(also added 12v adapter for GPS, which is a must as I avoid highways... that's part of the fun)
NOTE: the photo was taken before I moved the backrest forward.
posting the photos worked and I see another White is on board! 
