This is another expansion for the SampleTank 2 application. SampleTank 2 is a pretty good application that allows you to utilize all kinds of different samples to create whatever sound you can think of in your head. With all their added samples, it makes the application fairly versatile. However, the piano sounds on this are pretty average, in my opinion. I'll get to the sound quality in the second portion of this review. The application itself is fairly stable, and I never experienced any crashing. It's easy to use, and because of such, I never had to look at the manual to see what's going on. That said, the program can be very deep once you start going into everything. Depending on how well you know VSTs, you might want to take a look at the manual to see how everything works and interacts.
The sounds are what everyone wants to know. To be fair, they're average. The piano sounds like any other piano samples from most built-in VST applications that come with your favorite DAW. They sound a bit MIDI processed, and as a result, they can be a bit "fake" sounding when soloed. However, once you start adding them to a dense mix, it's pretty hard to tell that they're simply MIDI samples. I mainly use piano on things like power metal and the such, so my opinion as to what is good and not might be a bit different than yours. I definitely wouldn't be using these in some sort of classical setting, but others might prefer that. You'll really have to listen to the samples and decide for yourself.
Overall, the expansion isn't too bad. There are some decent samples, and it can deliver at times. However, I've used built-in synths that sound a bit better. Because of that, it's kinda hard to recommend. If you already have a solid DAW that comes with a nice set of VST synths and samples, this might not be worth getting. However, if your DAW is bare, these could be worth picking up.