While the new Thummer instrument has a myriad of advantages over a typical musical keyboard, there are some areas where the older instruments still hold the upper hand. In the basic C Major scale, it is easier to learn on the piano than with the Thummer. However, all of the other scales are easier on the Thummer. In addition, the chromatic scales can be more difficult for some musicians.
These basic problems can be conquered, but the major limitation of the instrument is its newness. There is no fundamental music theory for the Thummer and there are only a small number of professionals to teach the instrument to beginners. Until more teachers are present, most beginners will have to learn the Thummer without external help. Another current difficulty is the cost. The hexagonal keyboards make the instrument more expensive than a standard keyboard, but as popularity grows, the price will go down.