New shock and fork seals will be a little sticky until broke in. Also check for proper sag on the shock spring as well as compression / rebound settings. No two bikes are alike, that's for sure. Check also, any points that might cause friction. Mainly the pivot points on the rear linkage. Are his greased? Cause they sure do a poor job from the factory. For that matter are yours greased?
Unless you ride a whole bunch, don't keep your air filter clean, or have gummed up the KIPS, I would check the spark plug and pop in a fresh one. That is probably what the "snap" difference is. Could also be the difference in amout of tire life left, or heck, even air pressure. An over inflated tire will spin much quicker than a properly inflated one. How about your spark arrester? When's the last time that's been cleaned?
I really doubt you need to rebuild the top end in only a season. Keep us in touch with what you find out.