[rtheunissen]

Zip trees are novel but their performance (and therefore also skip lists, since they are isomorphic) lacks behind other linked structures like Treaps and especially LBSTs. [1] I personally find skip lists to be overhyped binary search trees in disguise.

[1] https://rtheunissen.github.io/bst

[bonzini]

Absolutely trees in disguise, in fact there are deterministic versions of skip lists that are equivalent to B-trees. An 1-2 skip list (where each pointer to next can skip from 1 to 2 pointers on the level below) is isomorphic to a 2-3 tree.

[hinkley]

I always felt like Pugh was pointedly ignoring the cost of inconsistently sized data structures and felt like more transparency there was necessary. It's been a really long time since I dug into them though so I could be out of date.

I'd also like to see better investigations into Treaps balanced not for fairness but for average access time, so that more frequently used values are faster to look up than uncommon values.