Furthermore, a (versioned, as always) path summary keeps track of all distinct paths, which is a key ingredient for the optional secondary indexes, which can index paths or paths and content among other stuff as simply indexing fields. Optionally you can also add indexes to speed up aggregate queries (which are basically column projections).

Furthermore, the whole storage can self-validate through checksums stored in parent pages up to the root as in ZFS for instance.

DeweyIDs can be optionally stored for each node, which can speed up the comparison of subtrees between revisions (in order to detect simply which changesets belong to a certain subtree without having to traverse ancestor chains). They lend themselves well for compression.

We even have importers which can identify based on heuristics minimal edit operations to import existing revisions of XML or JSON documents and to commit these with hopefully a minimal or close to minimal set of update operations, but it depends heavily on the data.