One of Kawai's most important innovations is the use of ABS Styran plastic in the manufacture of action parts. More than 40 years of use and scientific testing have shown this material to be superior to wood for this purpose. ABS does not swell and shrink with changes in humidity, so actions made with it are likely to maintain proper regulation better than wood actions. The parts are stronger and without glue joints, so breakage is rare. These parts are present in every Kawai piano. In the current Millennium III action found in some models, the ABS is reinforced with carbon fiber so it can be stronger with less mass. Having less mass to move (that is, less inertia), the action can be more responsive to the player's intentions, including faster repetition. Certain contact surfaces on the action parts are also micro-engineered for ideal shape and texture, resulting in a more consistent touch. Although it took a number of years to overcome the idea that plastic parts must be inferior, there is essentially no dispute anymore among piano technicians on this subject.

Kawai's vertical piano offerings change frequently and are sometimes confusing. At present there are three basic series of Kawai verticals. The console series begins with the 44½" model 506N, a basic entry-level console in an institutional-style cabinet (legs with toe blocks). Model K-15 is a 44" version of this in a continental-style cabinet (no legs), and model 508 is a 44½" version in a simple furniture-style cabinet (freestanding legs). Model 607 is the same piano in a fancier furniture-style cabinet. All have the same internal workings. The action in this series is slightly smaller than a full-size action, so it will be slightly less responsive. However, it is more than sufficient for beginner or casual use.

Kawai has replaced both of its former studio models, the UST-7 and UST-8, with the 46" model UST-9, made in Indonesia. This model has the stronger back of the UST-7, rather than that of the UST-8, which was not known for its tuning stability. The UST-9 also contains the Millennium III action; an angled, leather-lined music desk to better hold music; and a stylish, reinforced bench. The 46½" model 907 is essentially the UST-9 in a fancy, furniture-style cabinet. Rounding out the Kawai studios is the new Japanese-made FINO Interior Design Series of three models — the Gilda, Rosina, and Lauretta — that Kawai says are "European in style."

Kawai's K series of upright models comprises the K-2 (45"), K-3 (48"), K-5 (49"), K-6 (52"), and K-8 (52"). All have the Millennium III action; a soft-close fallboard; a wide, leather-lined music desk; a somewhat stylish cabinet; and come with an adjustable bench. The K-5 has Neotex synthetic-ivory keytops. The 52" models also feature agraffes, duplex scaling, Neotex keytops, and various kinds of tone escape mechanisms. The K-8 has a true sostenuto pedal.

Kawai makes three series of grand pianos: RX, GE, and GM. The RX, now in a version known as the RX BLAK series, is the most expensive and has the best features. It is designed for the best performance, whereas the GE and GM series are designed more for efficiency in manufacturing, with fewer refinements. The RX pianos are the only Kawai grands with a radial beam structure, focused and connected to the plate using a cast-iron bracket at the tenor break. This system makes for a more rigid structure, which translates into better tone projection. The soundboard of the RX models is tapered for better tonal response, and the rim is thicker and stronger than in the GE and GM models. The RX BLAK pianos use a new version of the Millennium III action with hammer-shank stabilizers, designed to retain power by keeping the shank from wavering under a heavy blow; have agraffes, duplex scaling, lighter hammers (less inertia), and Neotex synthetic ivory keytops; and come with a slow-close fallboard. The RX grands get more precise key weighting, plus more tuning, regulating, and voicing at the factory. The cabinetry is nicer looking and of better quality than that of the GE and GM series pianos, with the polished ebony models in the new RX BLAK series receiving a UV-cured, scratch-resistant coating on the music rack and music shelves.

Some of the RX features are also found in the GM and GE pianos, but it varies by model. The GM-10K is the only Kawai grand made in Indonesia. It has Kawai's standard ABS action, no agraffes or duplex scaling, standard keytops, and a regular fallboard. The model GM-12, made in Japan, has the regular Millennium III action (without hammer-shank stabilizers), no agraffes or duplex scaling, standard keytops, and a slow-close fallboard. The GE models, also made in Japan, have the regular Millennium III action, agraffes, duplex scaling, Neotex keytops, and a slow-close fallboard.

Kawai's quality control is excellent, especially in its Japanese-made pianos. Major problems are rare, and other than normal maintenance, after-sale service is usually limited to fixing the occasional minor buzz or squeak. Kawai's warranty service is also excellent, and the warranty is transferable to future owners within the warranty period (a benefit that is not common these days). The tone of most Kawai pianos, in my opinion, is not as ideal for classical music as some more expensive instruments, but when expertly voiced, it is not far off, and in any case is quite versatile musically. In part because the touch is so good, Kawai grands are often sought by classical pianists as a less-expensive alternative to a Steinway or other high-end piano. Kawai dealers tend to be a little more aggressive about discounting than their competition (Yamaha). There is also a thriving market for used Kawais. (If you're considering buying a used Kawai, please read "Should I Buy a Used ‘Gray Market' Yamaha or Kawai Piano?" on pages 176–177 of The Piano Book, or the shorter version in "Buying a Used or Restored Piano" in this publication.)