I picked this up and wanted to give some thoughts approaching this from a pianist as well as a programming perspective. First the good, the pedal behavior and adjustability is among the best I have encountered in a sampled piano library. The mic perspectives here are very distinct as opposed to some libraries which have as many as 8 mics, but they are not very distinct between many of them. The interface is clean, attractive, and easy to navigate.
As far as the basic sound quality speaking mainly from the close mic perspective, there is quite a bit of muddiness, particularly in the lower registers, and is not as clean as most other libraries, though I find the upper half of the keyboard range and treble to be acceptable and actually quite nice with hints of sparkle. There is a notable change in timbre around A2. While note to note is fairly consistent, it is easy to pick up the layer transitions, not surprising since there are only 8 layers.
Many of the samples, in particular the lowest velocity range, have a lot of noise such as rumbles, hiss, etc. Check out A4, pedal down sustain, round robin 1, lowest velocity layer for an example. Sounds like something being drug across the floor during the sustain. Another example is A4, pedal up sustain, round robin 1, 2nd lowest layer which has a double strike in it. I was able to play around with the mappings a bit which made a huge improvement in the overall quality and playability of the library. I also noted occasionally a hung note although I haven't found out yet exactly how to reproduce this. Not sure if the velocity to brightness control is working properly, any change is very subtle to non-existent with this control.
Out of the box, the velocity curve is set too low and to bring out the best sound, the curve needs to be increased quite a bit and then blending in the stage and/or hall mics to add back some brightness and ambience. Also moving the release up a bit helps with the abrupt note cutoff at the default setting. You also get a bit better repedal response as well given these are tied together. Generally there is a lot of potential here, but the library needs more work. I would suggest the following to the developer as a patch update.
1. Remove the noisy samples, particularly in the lowest velocity layer, by either stretching the layer above or a better option is to use the best of the two round robin samples for both RR1 and RR2.
2. Remove the A4, pedal up sustain, RR1 sample, 2nd lowest layer.
3. Fix the occasional hung note. As mentioned not quite sure of the source.
4. Maybe some alignment on the mapping around A2 to line up the timbre better in this region.
5. Look into the Velocity->Brightness control. I wasn't finding a huge difference if any with this control.
I think the above could be accomplished with a couple of days work. Longer term, a couple of suggestions for the next major version:
1. Add sympathetic resonance which most libraries have at this point. To do this clone the pedal up sustain samples to a separate group, move in the start to where the string is just ringing. Add in scripting to activate these notes when the key is pressed and a related harmonic note is struck. Add to the interface an on/off switch and volume control.
2. Maybe look into selectively applying AET to the few noticeable layer transitions. This would probably only work for the 24 bit samples as there tends to be artifacting with 16 bit samples.
All the above are strictly my thoughts and suggestions as opinions vary greatly on piano libraries. I think overall this would be a great library for recording or playing lyrical/emotive pieces. There is a lot of potential here to take it up to the next level.