I have just replaced mine with the TBS model and It is definately worth it. I am not a mechanic and was pondering whether to try and do this but I was amazed at how simple it was. I removed the rear wheel and while the wheel was on the garage floor i tried moving the hub. I'm guessing that i had almost 10mm of play in the hub.
I then removed the hub from the wheel and took out the old cush rubber and installed the new cush rubber the same way as the old one came out. It was a very neat fit and there is no play in the hub whatsoever. I took the bike for a ride and you cannot believe the difference. The gear changes were so much smoother and more direct.
Strangely though when I looked at the old rubber I cannot see any wear marks on it after 15000kms.
All the same I am very happy with the new cush rubber and can recommend you do it. part no. I used was T2012211
I took some pics and will add later.

Derek


2008 Black Speedmaster