The Nonken Triadic Memories is very much in line with the sort of middle-of-the-road, Feldman-located-within-the-comfort-zone school of performance practice that has become fashionable in the last 10 years or so.
Not qualities I even begin to recognise in her playing on this DVD. Nor does it seem to relate in the slightest to her own views on performing the work, as expressed in the video content of that disc. Indeed, something she found she wanted to get away from in earlier recordings she had heard was a lack of consistency in tempo. As you will no doubt be aware, the recording aimed to present the work as heard from the the audio perspective of the pianist, rather than what might reach the front row of the audience.
I tend towards Kyle Gann's assessment:
There's such a temptation with Triadic Memories…to smooth out the prickly rhythms, and let the music float and turn ambient. Nonken resists. Her rhythms twist and turn with Feldman’s peculiar notation, and her tone color, though soft, is melodically urgent, not self-effacing. It's a dynamite performance captured on a spectacularly pristine recording.
I certainly find this recording no 'background listening' experience, though I do go back to the Tilbury CD, piano and recording quality notwithstanding, with fresh ears. Nonken, of course, did not have the opportunity to know Feldman, coming across his music for for the first time as an undergraduate, not long after he died. She has, however, worked with, and learned from, many musicians who did work closely him, especially Joan La Barbara. I do not know her CRI recording of the Finnissy, but noting just how bargain basement its price has become on Amazon.com, I think I will give it a miss.