For many years, I had run a site on Drupal 6. For some reasons, continuing was no option, as was migration (upgrading). By the way I have to thank Drupal 6 for, all in all, forgiving me more than one basic mistake (my first Drupal project ever) and serving pretty stable along some five years. Which is good. Despite this, I am happy that this performance hog now sleeps (almost) for good.