My first 1200 came hilltopped, so can't comment on improvement ... but still ran like a lumpy bag of shite after 5 years on a Honda.
The twincam was far better than the hilltopped bike, and in my opinion needed no fettling.
The WC has ample power & I wouldn't dream of messing with it.
If I want smooth turbine performance there are plenty of options out there.
I can't comment on the Euro4 model, but neither can everybody in this thread planning on getting it done.
Att summed up this section in the pub with his "not knowing what to spend their money on next" comment.
Take a 15 grand premium best selling motorcycle and throw £350 at it for a software update.
If it were a track day GSXR1000, for sure Geoff is the man - I agree!
But c'mon, a quartet of fat middle aged tossers handing over a grand for a mornings work to enhance their twin pot tractor needs to consider supporting a local charity to enhance their lives.
Hope this enlightens you!