Since I have yet to write my own review of Final Fantasy IX OST, I'll mention that I think it's very much a successful tribute to the classic days of the series, and taken as a whole is the best FF original soundtrack since FF6. Not bad, eh?
In similar fashion, Final Fantasy IX Piano Collections successfully emulates classic FF piano collections. I've not heard FF8PC, but I can very much sense similarities between FF9PC and its SNES-era piano collection counterparts... not only in the style of arrangement but even in the track selection and overall presentation. As far as overall quality goes, I would place it somewhere between the overly simple FF4PC and the remarkably dramatic FF6PC.
Had I really studied the track list before buying the CD (it was an impromptu purchase at the FF9PC live event in Tokyo), I probably would have been a little skeptical about the CD, since not all of the selected tracks exactly count as my favorites on the OST. But as is the case with any well designed piano arranged album, the producers (Uematsu-san, actually) chose to include not only the tracks that work best in the OST, but also tracks that would flourish in piano form. For instance, I usually skip "You're Not Alone!" in the OST, as it sounds cliched. But the piano version is quite a different matter, as both the arrangement and the piano itself avoid the failed, modern-epic sound aspirations of the original for a less serious and more accessible feel.
Uematsu has a tradition of including battle themes in his piano collections, and FF9PC's "Final Battle" surprisingly comes across much better than the OST version. Chalk this up once again to being less cliched, both in arrangement (it's slightly toned down from the overly eager OST version) and in the very use of piano as instrumentation.
Another logical but not necessarily successful tradition in FF piano collections is giving tracks that were piano synth in the OST a try with a live performance. This does little to salvage the boring OST version of "Sleepless City Treno" (I liken it to "Spinach Rag" in FF6 OSV and PC). Fortunately though, the melody of "Rose of May" retains all its wonderful beauty in the live version and is diversified a bit by the more elaborate arrangement and performance.
Finally, there is the question of whether stand-out OST tracks can maintain their quality when altered and performed by only a solo piano. In the case of "The Place I'll Return to Someday", the dignified and lovely sound of the piano indeed adds to the already pretty OST melody, although the just slightly jazzy turn the arrangement takes halfway through is in my opinion not the best choice. Most would agree that "Vamo' alla flamenco" is one of the more memorable tracks from the OST, and maybe one of the hardest to pull off in piano form. This piano version does indeed manage to keep much of the energy and liveliness of the original, and would be a lot of fun to play, I imagine. Lastly, who can question the inclusion of "Melodies of Life"? Although it lacks Emiko Shiratori's lovely (in Japanese, at least) vocals, the melody works well in the new arrangement and the piano adds a loveliness of its own.
The one complaint I can already hear some people levying against FF9PC is that it is too simple. And I agree, the arrangements are a bit on the simple side. Nowhere near as simple as they could be, mind you (FF4PC and Ys Piano Collection prove that), but there are certainly times where I can envision the arrangements having some more spice to them.
Final Fantasy IX Piano Collections is almost as much of a pleasant surprise for me as the OST was. It doesn't manage to tug at my heartstrings the way some previous FF piano arrangements like the Final Fantasy 1987-1994 version of "Dear Friends" and several tracks from FF6PC did (even though a couple of the melodies included here had the potential). But it is certainly an enjoyable, faithful piano version of a memorable Final Fantasy OST.