I have the Yosh R77 full carbon and would highly recomend it! Carbon just has that bling factor!
As you know a PC is not required(I didn't get one)and the performance gains are very noticeable and from what I've read, it could be slightly better if down the road I decide to get one.
The sound to me is pure perfection. Just the way I wanted the pipe to sound. I took the removeable silencer tip out and that gave it just the extra bark I was looking for. But it's nice to have the choice of two db levels.
Last, I did the install myself and I'll bet if you put aside an afternoon and take your time you can do it yourself too.
Hope this sticks to the point and answers some of your questions.