Ahh well that's the thing I was wondering, basically there is only so much you can do with an end can externally, but the coned end does seem to be getting more popular.
Never had BOS ( had most others in combination with Remus headers) but have read good reports from other users and as I'm a firm believer in ditching the cat thought this looked worth consideration.
Owing to circumstances beyond my control I've not had a chance to ride with the GTS system fitted, but I've seen it and heard it running and was pleased with both experiences.
I particularly like the use of a bolt on mounting bracket rather than a strap. Build quality seems top notch and the mechanic who took it out bask to back for a test run with another bike with the stock can and headers reported it ran smoother.
I was about to post about my new BOS system. I had to replace it due to a prang on my way in to work that scratached the OEM s/s can and dented the down pipes. Couldn't have got it past SWMBO otherwise. Opted for the BOS carbon fibre end can (not sure it is a GTS) with the cool coned end.
The bike sounds fantastic. I never thougth I would be the sort to blip the engine at traffic lights, but its almost irresitable. It also pops slowing down from high speed. On the less emotional side it has saved 4Kg and increased the mid range power. This makes the bike feel much smoother in traffic,and when filtering. I can't say that I have noticed a big improvement in overtakes or top speed. but I enjoyed blatting round parts of Oxfordshire yesterday. It is early days yet, but I think I may be paying for this in higher fuel consumption. At the moment I don't care.
I will send a picture tonight if I have time.
Regards,
Path
P.S I have the original system to sell if anyone is interested. I will post it on FS&W when I have some pics.