I have the commander and the Akropovic can, on the fazer, and I noticed a couple things: the can gives the bike a quiet sound at low rpm, and a mega deep throaty sound at high rpm. No feedback on power increases.
The commander pretty much makes the engine into a freakin rocket past 5k, and this can be modified, I understand, with various commander power maps. I left it the way it is as it reduces shifting in city stuff.
I have no idea about top speed, because after 160 mph, I usually run into traffic. But it has PLENTY more left, without a doubt.
You trying to go in a circle faster? Just kidding, do what you want, but do it with safety, caution, and respect for local traffic.