I own both an Imperator V and a Morino VI N, love the Imperator, but the keyboard is a distinct notch under the MORINO, both left and right hands. Here is an odd fact… Imperator V, hand made reeds, MORINO N, hand finished reeds. Never can understand why Horner would do that.
My opinion is that Morinos were made for more specialized music and the Imperators made for greatest versatility. Both aimed more towards the professional musician, looking at the literature and line-up of Horner accordions at the time.