Do you think the backrest is worth getting?
When I bought my 'bird, I had the longhaul seat fitted as the standard passenger seat was much to small.
After about 100 miles, I get a pain in base of my back, right on the bottom of spine. I ordered the back rest and it has helped a little.
There have been some posts, that it pushed you forward on to the tank. For me it works OK, I have it on the last setting all the way back.
I do like the extra support of the back rest, have just ordered an Air Hawk 2 seat pad to see if this helps.
This is the only problem I have found so far with the bike, a sore ass on a long run.
Maybe if you could find a 'bird with a rider back rest, you could see how it feels for you.