Love my S&B, not very loud but you can still hear the V8!
As for numbers, MPG, HP, etc - yeah I don't think it did anything lol.
Wouldn't use the plug unless I was regularly off road in muddy waters, no experience with the scoop.
Here's some pics of mine - looks very OEM - no scoop though...
Extremely professional kit, very well put together, excellent instructions etc.