When I bought it my 350 K Sport had been fitted with a 40 tooth rear sprocket instead of the standard 38 tooth.
Logic (and motorcycle lore) suggests that this should have made it a better ride - better acceleration through the gears and more thrust in top gear.
It didn't. It left the bike feeling 'busy' in top gear while cruising, and I was constantly swapping between second and third round town; I seemed to have a wrong gear of every situation.
Going back to standard sprockets front and rear - which I initially did just so that the brand new chain I inherited from the previous owner would fit - made a much bigger difference than I expected. The gears feel slightly more spaced out, top is a little more relaxed, and.. in fact, here's what I wrote at the time:
"Top gear is now a motorway and dual carriageway overdrive, but fifth has become a really useful general gear with enough punch for overtaking without having to scream the engine. And because the spread between the gears has been opened out, the bike actually feels more tractable. I was really surprised how much difference this made, particularly at Cadwell Park where the gearing now seemed "right" for more corners, more of the time. Don't believe people when they tell you that dropping the gearing will make your bike faster; for me and my Morini, the opposite was true."
I'm all in favour of tinkering, but in my view it's just a nicer bike on standard gearing.
Gearing on my Morini:
http://www.realclassic.co.uk/morini05101400.html
That yellow Strada that was in Motorcycle International:
http://www.realclassic.co.uk/morini030521.html