Should we consider using GUIDs rather than incrementing integers for primary keys?

[theninja]

I feel using GUIDs (partially sequential - MySQL 8+ seems to come with built-in support for these via UUID_TO_BIN) for our primary keys gives us some quite nice benefits. I'm thinking towards the future for scaling/replication and generating indexes on the front-end (possibly even in some kind of offline mode). I guess this would also make merging separate databases easy, which might be helpful for future migrations.

We would need to discuss some of the cons too, like disk usage (16 bytes rather than 4 for each key) and any performance costs (I've never used GUIDs in MySQL before).

Although not a priority, it's a fairly simple change that would make sense to do before any real sites are using the system. Any opinions?