BMack,
I bought Akra headers to feed yooshimura R77 slips. The Akra set up did zero for the bike. Other than weight savings I got no enhanced sound and zero performance increase. I'd recommend splurging for a full system instead. That said my brother Cblast just installed the akra header to feed muzzy slips and he reported a slight performance enhancement. C can chime in, for me, not worth the additional cost and install.
Mad love
Wman