I can vouch for the grom performing somewhat better once it passes the break in period. I wanted a little more top end power and a higher top speed so that i could ride on 55mph back roads and not get run off the road. I did the Brock's exhaust and the sprint filter chimera intake along with a power commander. I have the luxury of having a nearby friend with a totally stock grom to compare. The benefit of these modifications is mostly in power up to top speed...so acceleration gains for sure. My top speed increased, but also can be cut back to the original stock top speed by a strong head wind. An unexpected or unintended byproduct of the exhaust is the grom also sounds badass. Hope that helps...even if it isn't directly related to sprockets, I thought it might address what you are talking about.