I haven't ever experienced problems with data not being available on MySQL either. Running several Drupal 6 & 7 sites on MySQL. Also, the company I work for hosts their main customer interface against on MySQL and they haven't had any problems in the several years it has been running either.
Is that an issue from 'ye olde' days? I love your posts, but from what I am reading here, it seems like some have problems with bugs in MySQL that aren't actually there anymore. Either that, or I have just been insanely lucky to not have experienced any of them? I'm running Debian stable with apt sources from (http://packages.dotdeb.org stable). So my MySQL version is 5.5.30-1~dotdeb.0.
I couldn't blame you in that regard though, once something leaves a sour taste in your mouth, it's hard to find reason to go back and try it again, I've done the same thing. Though this article is definitely inspiring me to have a look at both PostgreSQL and MariaDB. One gripe I had before (in drupal v6 about 2 years ago) was that PostgreSQL was purported to not support a 'distinct' select by the maintainer of the 'views' module (or possibly a random committer?). It made some of the configuration that I tried to do with views not work out correctly, so I ended up hacking the module code to add distinct support.
Drupal v7 now has a database abstraction layer though, so it now supports specialized queries based on whatever DB you choose to run it on. Drupal 8.. haven't tried it yet, but I looked at some of their DB code using PHP 5.4 traits, and it looks pretty slick. I'm was planning on putting together a new VM soon for testing out Drupal v8 on PHP 5.4, I'll definitely give PostgreSQL and MariaDB a shot.. though http://packages.debian.org/testing/database/ doesn't seem to have a package for MariaDB, looks like mariadb.org has its own repos: https://downloads.mariadb.org/mariadb/repositories/.
Should be fun!