Same here.My Grom reaches a "decent speed" everytime I ride it. Is it decent for a 250-300? No, it is way too low. Is it decent for a 49cc scooter? Oh heck yeah it is way faster than any of those. Is is decent for a $3000 125cc economy Monkey bike? Yep - does just what I thought it would do.
My engine has never seen 9,000 rpm and has only seen 8,000 a couple of times, because I just use my Grom as a useful tool to carry cargo and to take me places I need to go.
I enjoy my Grom for what it is.