It's amazing how fast you can go when you don't care about safety ;)

That said, for all non trivial work loads, the latest postgres is quite the work horse, but of course requires some tuning for performance. We ended up switch to it after MySQL consistently sucked on smaller joins.

Can't argue on the replication deal: it's a work in progress.

For any reasonable RDBMS deployment resources PostgreSQL has been faster than MySQL for me. Write-heavy loads are a huge win for it, but even on large reads (formerly its weakness) PostgreSQL has the advantage unless you've got no writes at all on the table. I guess if you've got completely static data MVCC isn't a win, but at that point I'm not sure you need to be using an RDBMS in the first place...

If it's an embedded system, why not use SQLite instead?

> Speed :)

At the cost of ACID. In my experience PostgreSQL is faster than MySQL-InnoDB.

Replication is dead simple now, but a few years ago it was not.

Postgresql is generally faster than mysql. Fitting it onto an embedded system is either memory or storage constraints, but postgresql is equal or better in both those regards so I can't imagine what problem you had. Replication is dead simple with postgresql as well, with the added bonus that it doesn't randomly die and require manually intervention to get it working again.