Mine is an F228 that has what I would consider typical Fazioli characteristics:
1. The tone is exceptionally clear across the whole keyboard, but this proves especially interesting in the upper two octaves where you get a richness and sense of overtone that is lacking in many other pianos.
2. The sustain is unusually lengthy and in fact takes some getting used to. You have to learn to use the damper pedal judiciously or you will get muddled sounds. Many pianists take a half hour or more to get familiar with this and adjust their pedaling, and sometimes the Fazioli is unfairly blamed for those who can never make the adjustment.
3. The instrument requires careful and sensitive voicing but the results should be spectacular; each hammer has the capability of producing three or more tones depending on the pressure used. Once you adjust to this, your ability to add color to your playing is greatly expanded. The Abel hammers are always properly voiced when they come out of the factory (Paolo Fazioli sees to this personally), but in some environments the instrument brightens up in the showroom, and the piano has gotten the reputation for being too bright or strident in its tone. This is entirely because the voicing is not maintained properly, since with reasonable care the hammers are capable of generating expressive sounds.
4. The aliquots do not need to be adjusted too often but can be when necessary if you are hearing discordant partials. This can be an advantage over other instruments where you simply must live with these problematic partials.
5. The action from the factory is very supple and should permit complete technical performance for any decent pianist. There have been a number of improvements in the Fazioli action over the years and I would consider it among the industry's best, though Kawai, Steingraeber and other manufacturers are also making great strides in this area. Along with the tonal capabilities of properly-voiced hammers on the instrument, the flexibility of the action allows for a very natural keyboard. In other words, as many have said who play it, there is very little between you and the music - you don't have to worry about the instrument when performing, and you can desire some effect in your mind and discover the instrument will deliver it.
6. Volume production is substantial, and as a consequence an F228 or even smaller Fazioli can be suitable on a small stage for solo or chamber music. The downside of this is that you have to be careful when buying one for your home that the music room is large enough to accommodate the volume.
7. Because of all of these sensitivities, the instrument requires somewhat more care and maintenance than other pianos such as a Yamaha, which has a more standardized, mass-produced quality that assures consistency and stability across the brand. But particularly if you keep humidity and temperature relatively stable, the Fazioli will have highly stable tuning (maybe once a year for thorough tuning), and regulation and voicing are mostly touch up matters.
8. Due to these sensitivities, the instrument is ideal for amateurs and many purchasers are amateurs of modest financial means who are willing to sacrifice in order to obtain the improved performance capabilities that a Fazioli allows. A select number of concert artists prefer the Fazioli, but of course the concert world is dominated by Steinway, and there are consequences for Steinway artists who stray from the fold. You won't therefore see many Faziolis on the concert stage, also in part because there haven't been that many concert grands coming out of Italy, since only about 100 pianos a year are produced. However, most large cities now have showrooms with Faziolis, making it possible for amateurs to try them out.
9. Finally, I have played a concert grand with the fourth pedal, which is a typical half-blow that brings the hammers closer to the strings. The effect is a hushed sound, that becomes even more ethereal if you add the una corda. In fact, it is impossible to play above mezzo forte when using the fourth pedal. Though I don't have this on my own instrument, it is certainly a useful addition for tonal and coloration purposes, and with the right pianist could provide some unique performances/ recordings. I should note that, because of the very long sustain of this piano, I find that a light touch of the sostenuto pedal can be very effective rather than using the full damper pedal. Therefore I am playing more than ever with the sostenuto as a delicate version of the damper where a long tone can be emphasized (Rachmaninoff has many such circumstances in his music).