Re: (drthompson65)
I'd bet my 50mm system would work great on your 999 without a Powercommander.
The problem you will find with any aftermarket exhaust is they are really designed for racing and give a strong hit at the top end, at the expense of midrange. If your bike is a street bike, that's the last thing you need. That's why I removed mine. I loved the sound, but hated the midrange hole.
But, being 50mm, I wonder if it wouldn't be the ticket for your 999...I'm not trying to sell you a pipe, but would love to hear from the experts on this theory. Then I'll try to sell you a pipe!