[skyfaller]

I guess my concern about subtrees is that they seem like they can result in unnecessary duplication / use of disk space. But the ability to work offline with a complete copy of the code seems worth the tradeoff in most cases, and git-lfs should help deal with large file sizes.

Have you run into any "slow push speeds" with subtrees, as the person complains about in the first article I linked?

[ddevault]

No, I haven't run into any such issue, though I have only used it with small to medium sized repositories. The repo simply grows linearly with the size of the secondary repository. With a submodule, you would have to clone it just the same. In fact, you might enjoy some benefits from cross-compression by using subtrees that would not be available to submodules, and it's faster to reuse the same clone connection you were already getting the source from.