I bought an aftermarket can for the Honda.
First impressions were,
1 Mmm that sounds nice
2 Feels like it has more power but probably just sounds like it has.

Now after riding about 500+ hundred miles I have noticed that the engine's a lot more free revving, definitely has more pull but the biggest surprise and one I wasn't expecting is that it's now a lot better on petrol
I was getting average 50mpg with the standard can but now am getting 58mpg and on a slowish trip down to Bournemouth yesterday I got 62mpg

Bought the can 2nd hand on fleabay for £50, at this rate it will have paid for it's self in no time 8-)

So anyone thinking of buying an aftermarket can do yourself and your bike a favour and get one ASAP