I don't have an exact number in mind—I imagine it's pretty context-specific—but 500–1000 nodes seems like it would qualify. I've played around with IntMap befo

I don't have an exact number in mind—I imagine it's pretty context-specific—but 500–1000 nodes seems like it would qualify. I've played around with IntMap before and it's not a great data structure. It's a binary Patricia trie, which means that you quickly get a relatively deep tree with lots of pointer traversals. Unless I've managed to confuse myself on how it works, you'd end up with, what, at least 10 traversals to look up a value from 1000 keys?