There is a lot of misrepresented facts posted here.
How old was the angled valve which was installed on the front wheel?
You will need to balance your wheel every time you change a tire, so adding angled valve will no unbalance your wheel, since you will have to properly balance it after...
You should really look into the price/benefits. On the R6's the benefits are very minimal, not too sure how heavy the factory FZ6 wheels you have are. Unless you really have some extra coin to spend, then, please share your pictures with us once you pull the trigger :)