Two aspects of the Seiler piano that really stand out are its sustain and its tonal clarity. Perhaps the biggest contributor to these is the soundboard design, which allows for both stiffness and flexibility where each is most needed. You can observe this aspect of the design by looking at the soundboard where it meets the rim and noting the distinct taper at the soundboard's edge, which provides greater flexibility for this normally stiff area. Equally impressive is the rim structure. A look underneath the piano will reveal laminations of several types of wood, in a combination intended to provide a balance of structural rigidity and tonal quality. Design and construction elements such as these, which are unique to the Seiler piano, are testaments to the instrument's quality. Seiler has also taken great strides to create tonal clarity by preventing false beats — tonal irregularities in individual strings, often caused by poor termination of the string's speaking length — and its treble is truly one of the cleanest-sounding in the industry. The Seiler piano's Renner action is what you would expect from an instrument of this caliber: responsive in controlling both dynamic range and repetition speed.
Having serviced Seiler pianos on the sales floor, I've had the opportunity to see them as they were being unpacked after having been shipped from Germany. I've been amazed at the condition in which they arrived: in good tune, and with accurate regulation and consistent voicing. I've also been able to compare their tuning stability with that of other brands, both high-end and consumer-level, and have been impressed with how well the Seilers remained in tune — given identical environmental conditions, the differences in tuning stability were noticeable.
At this level of quality, it's virtually impossible to pick a bad instrument. However, some pianos will better fit your personal preferences than others. Many pianists would characterize the Seiler piano as leaning toward the brighter end of the tonal spectrum, distinctly European in timbre. A competent technician can alter this to some degree, but if you prefer a darker sound, other brands may be a better fit. It should also be noted that Seiler pianos can produce a lot of sound. While this should never deter you from buying a piano whose tone and touch you love, in the home, you may want to consider adjusting the room acoustics as needed with appropriate furniture, floor coverings, or wall hangings. In an auditorium, you'll be pleased with the piano's projection. Regardless of your preference, however, if there's a Seiler available near you, it would definitely be worth your time to experience playing it.
— Joel Haasenritter, RPT