How many bytes is a node, in practice? If you stuff hundreds or thousands of pointers in a node, plus a bunch of log, isn't that a lot of data to clone when you do a path-copy? It seems like there's a major trade-off there, unless you always write in large batches. I suppose you could have fast "cons-ing" of events onto the root log without any copying. It would be interesting to know what choices lead to good performance in a sample use case.