Yes.. it is both slightly louder and LOUDER. Appearing slightly louder at speed to the occupants of the Morgan which is where it matters. But below 20mph it does a good impression of a taxiing light aircraft which will activate perimeter car alarms on acceleration.
I bought a dedicated sound meter to see just how loud it actually is. Surprisingly, the Stage 1 is half as loud as an unmodified miniature dachshund.