Just for shits and giggles,
the Sil Motor exhaust I had here (54mm full titanium) was nice. But - it was large, even larger than the Termi I had on my SPS 2007. So you had some clearance issues with the rear wheel if you weren´t running the wheel eccentric far back.
When I went to my dealer to enquire for an exhaust system he told me to stay away from the really big Sil Motor system, because they had race systems there that were of horrible quality.
But then, I have seen newer Termignoni systems that just suck. Not well built and seemingly just randomly welded together.
If you want quality and money is not your main concern, go buy Akrapovic.
It appears to me that no matter which model of bike you own. You can always buy the matching Akrapovic system and you will have build quality and power. Has been like that with my 2000 R6, my buddy´s SC59 Fireblade, the 1098s (just look at the headers of that thing!) and my other friends 2008 ZX6R.