I am purchasing the HMF Performance series exhaust for my sons 2009 Rancher AT, and I am considering the EFI optimizer as well. From the forum, I understand that you can do the slip-ons without the optimizer, but you may not realize the potential performance gains. I'm reluctant to get the HMF optimizer due to lack of space to put the screen. Does anyone know of any alternatives? Are there any Rancher pilots out there who have the optimizer that can share their thoughts?