Hello Adam, welcome to the forum. Let me start by saying “YES” the difference is significant. The Hohner Piano 36 is a much better melodica than any of the melodicas you currently own. The Professional 36 and the Solist are yet miles apart from the Piano 36. I own several Hohner melodica the best being my Solist. The Pro 36 and Solist have a wooden interior and individual single reeds like an accordion, the piano has a reed plate with reeds attaced to the plate like a harmonica on a plastic body. These individual reeds on a wood frame give the melodica a warm rich tone unlike the piano 36 that has a bit harder tone. The only Melodicas that have individual reeds besides the Pro 36 and the Solist are the Vibrandoneon, Eolina, and the Clavietta, these are the Best of the Best. When I said that the Piano has a clanky keyboard sound that would be accurate in comparisons to the Pro 36, Solist, Hammond 44, Hammond Hyper and Vibrandoneon or even the top of the line Suzuki melodions. Not many have played the Pro 36 and Solist so I can understand when people say that they sound the same. I have been playing for quite a long time, and wish that Hohner had never stopped making the Pro 36 and Solist, these are the true professional melodicas once made by Horhner for the professional. Now the piano 36 is the last great melodica made by Hohner, there has not been a better one made since then. The Superforce, performer 37, Airboard, have all been geared for the student and not the professional. If you play your Piano 36 and one of these you will hear a big difference. I list the melodicas used at the end of the Monster of Melodca’s YouTube Videos so everyone can here what is being used. Check them out and see if you can tell the difference.
Monsters of Melodica