I think it’s a bit of shame that GetKeys on lists was deprecated in 2.0 as it had uses that aren’t fulfilled directly by the new dictionary nodes (as far as I can see—I may be wrong of course!) such as quickly getting the indexes of a list for when I wanted to later reassemble them after boolean filtering and stitching back together again.
Anyway, I now use DesignScript when I need that functionality in 2.0:
