Aside from looking about a million times better than the factory exhaust, I am quite pleased with the boost in performance from both the slip-on exhaust and especially the Bazzaz tuner.
I drove the bike for a few days with just the Arrow exhaust on it and it definitely helped out in the mid-range performance of the bike, even without the tune. I tried it with the baffle in and with it out. With the baffle out it is LOUD. It sounds like a dirt bike with the muffle cut off, definitely not a fan and the bike felt like it lost torque versus with the baffle in. With the baffle in the bike is about 30% louder than stock and you get a big boost in the mid-range performance of the bike (plus is sounds amazing - for real, it really does sound good not just loud). The tone is nice and deep and burbly and not too loud, I love it.
I installed the Bazzaz tuner this morning and took it out for a spin. It makes the bike feel like a completely different machine. All the low-end bogging and surging is smoothed out. Instead of that mid-upper dead range you have with the stock tune you now get a nice big surge of torque. If you're cruising at 50 in 6th gear and you give the throttle a twist it will actually accelerate instead of just bog and complain. Really the best way to describe the performance is "smooth". I have yet to see what it's going to do to my mpg but right now I say it's worth it.
Also, an important note with the Arrow exhaust, there are no instructions with it but it's pretty simple to install. If anyone has questions about the process just let me know, I'd be glad to help.