From what I read, there too much potential for vacuum leaks. In my case, the hoses are original and may certainly leak, but I don't feel like paying to replace them all. Many say that their bikes run better without, so I will remove it but keep the components. It's also inconvenient working around it.
Curiously, my son's 2006 Ninja has the exact same system. You would think the technology would have changed over the years which leads me to believe that it doesn't work and is there to put on a show for the US EPA.
1981 KZ1300, '98 Suzuki GSF1200S, '80 Honda CT110, '11 Honda CBR250, '75 Honda CL360, '00 Honda XR100R
Speak softly and mount a fast bike.