Yep, mostly sound, but that is lacking in the OEM system..
Exhaust by itself isn't the best performance mod. I imagine a good catback with tuning via Predator might net 5-10 RWHP, if that.
The above combo with simple head work, maybe a cam change, proper exhaust combination might net 50 or more RWHP (elaborate upgrades can get you more, of course). Its about the system and how it works together. Exhaust is finicky... you kind of have to go with an established combo... or else you need to run dyno pulls on a couple of different combos to get the right one for your particualr setup..
My .02... someone else will give theirs soon. Maybe look around the site and see what's listed
here:
http://www.300cforums.com/forums/performance-modifications/
Bottom line... looking for sound... BBobs is a good deal for 100-150 bucks. If you want more performance, look at doing some minor airflow changes with a tuned exhaust.... check out our supporting vendors, many have experience in this alley..