I use it in my 07 but I added the IDS also and at this point I don't have any 5th gear wine or clattering at all any more. I can't say that the Spectro did it because there was the two things I did close to each other, but it does shift better and I attribute that to the Spectro. Finding neutral is easier too. IMO, it's worth the price for a quart.
Have you done the IDS yet? THATS worth the $$$
New IDS Drive System - Harley Davidson Community