I have to tell you that I'm not a lover of a lot of modern music, and when I saw that were 17 mins of your piece, I thought I wouldn't get through it all, but then I did listen to it all and I liked quite a lot. I suspect that given several listens, it would grow on me even more.
The only things I didn't like were the flute trills. I wasn't sure if was meant to be a trill or if you were looking for the exact sound that you present in the piece, but it did (for me at least) spoil the aesthetic a bit. I use Sibelius too and you can change the length and speed of the trills if you want, or even just write them manually if it doesn't sound as you wanted, it does spoil the look of the score to do it manually, but at least it will sound as you want. There were also a couple of clashes in the piano that sounded a tad too deconstructed for me, by that I mean that it sounded like a fist just hitting the keyboard, again that probably is exactly what you wanted, but it did jar me a bit from time to time.
Apart from that, I did buy into the mood and the drama of the piece and was held there until the end, which for me with a modern work, is no mean feat.