I have Blackburn racks, an MTF-1 up front. I chose a platform rack after reading Ken Kifer's rationale for rack-top bags instead of handlebar bags, but I wonder whether he knew about bags that mount on decaleurs/brackets. Next time, I might forgo the platform.

Edit: My bar-end shifter cables kind of get in my bag's way; that's one reason I think a handlebar bag might have been better.