Just me 2 cents...
I tried a Jardine system on mine, which I found to be too loud and annoying. I've heard Vance & Hines Cruisers on 1100s and they sounded better, but still too loud for my taste. I wanted some thing that let out the low rumble but not wake up the neighborhood when I took off in the early morning rides.
I have since went back to the stock mufflers with the baffles removed (holesaw mod) with the cross-over tube blocked off which is just about perfect. And since I switched the air filter to a Unifoam filter, I re-jetted with a stage on kits. I did not gain much peformance, just the deeper sounding exhaust.
With most after market exhaust systems, you won't need to rejet unless you change to a different air filter, but you will need to open the air mixture screws a little to prevent running too lean. Also you will not have any difference in performance to speak of, just a louder exhaust.
Stock exhaust, with hole saw mod (07 Spirit)
Noise? Yeah, Some, definitely louder, but not as loud as aftermarket
Sound? Warm, deep, throaty
Performance? Couldn't tell you honestly if there is much difference.
Cost? $25 for the mandrel and hole saw bit
Installation? 10 minutes of cutting.
Very happy overall, and will suffice, until I can figure what I want and how much I want to spend.