With the size of it, I don't think the sound will change an awful lot with more age.
As far as putting a tune on it, It looks like your not much over an open header. Generally pipes sill have some backpressure to them that the carbs will enjoy a little tuning. With this new muff, I'm about sure a little tuning will be in order as I'm thinking that your going to be on the rich side.
A good dyno that shows the a/f mix will give you the info to get back on check. At $60, thats a good deal too.