Hello Ofir, One thing that will change the dynamics of even the best Melodicas is how they are played in triads, and the voicing of those triads. Consideration for overtones in melodica tuning as in accordion is very important to the overall sound. I tend to tune my Melodica’s slightly sharp in octaves (1) cent to thicken the sound, but not enough to feel that you are out of tune when played with other instruments. Another issue for consideration is that not every melodica will fit the sound you are looking for, what may sound good for one musical piece may not sound as good for another. I have recorded using many different melodicas in combination, but when in solo I tend to look for a specific sound that fits the musical piece. And last, the statement that Daren makes that there is not much difference in the lower cost melodicas is true as the basic design of the reed plates body and vary slightly. Once you jump to a melodica that cost several hundred dollars the reeds tend to be of better quality and the tone tends to be more defined. Good luck in your search.
Monsters of Melodica