From my previous research: (not my pictures)
The FZ1 bar has less angle and no rise (ie: it is flat)
FZ6 on top, FZ1 bottom:
The FZ6R bar has the same angle as the FZ1 bar but the same rise as the FZ6 stock bar.
FZ6R on top FZ6 on the bottom:
So basically if you have wrist pain because of the weird stock bar angle but enjoy the straight seating position try the FZ6R bar.
If you want the same nice angle but with lower handlebar and a bit more forward lean go for the FZ1 bar.
I went for the FZ1 bar and am really happy with them, the bike feels more aggressive and more flickable while still being very comfortable even on long rides.
I don't feel to stretched (i am 6'2"), but like the more aggressive riding position, it is a lot easier to tuck low and it doesn't hurt my wrists.
Here is a very good comparison made by ERCI: