It is far too soon to judge the relative standing of this release in relation to the trio's output. Standards 1 &2, and Changes are all unparalleled masterpieces.
Prior to this release, the most 'recent' trio release was 'Yesterdays', which was recorded in April 2001. Before that came My Foolish Heart, which was actually recorded in July of the same year; then The Out-of-Towners, also curiously July 2001; and before that Up For It, which was actually recorded live in July 2002.
And what was happening between 2002 and 2009 (when 'Somewhere' was recorded)? Answers, as they say, on a postcard, preferably from ECM hq in Munich. I suspect that Jarrett is exercising too fastidiously controlling a hand. I for one would value a 5 or 6 cd set documenting these missing years. It would make the label some money. It won't match the Blue Note box in quality, but perhaps no piano/bass/drums trio ever will.