I fitted one over the winter but hadn't had a chance to try it until yesterday, I did just over 200 miles up around Tydrum, Inverary then back down Loch Lomond side. The roll on acceleration is improved, come up behind a car, wait for a gap to overtake then woosh! Quite a bit crisper than before and i remember thinking how smooth the engine is on a cruising throttle.
Jim.