Does systemd's journal still use a binary format? That is a no-go for me. Inevitably it will get corrupted, and then you rely on the journal reader being able to recover your logs, or fix bugs in it until it does.
I'd be more willing to consider systemd as an alternative if it kept using a human-readable log format, that can be read with cat/tail in a worst-case scenario. If it wants to index it, it can keep an index on the side, no big deal if that gets corrupted/out of date, as it can always be rebuilt.