> it is still bothersome that changing a single character in a 50 megabyte presentation causes one to burn through 50 megabytes of the finite write life on the SSD.
I used to worry a lot about this but it has never once actually come up for me. 50 megabytes is a pretty extreme example, but even so if you edit this document fewer than several million times it won't matter.
Serializing the object graph all over again can be way faster than mapping into a tabular model. There are JSON serializers that can push multiple gigabytes per second per core. It might even be the case that, once you factor in the SSD controller quirks, the tabular updates could cause more blocks to be written than just dumping a big fat json stream all at once.