I perform a lot of Drupal updates, and they mostly go very well. The code updates without incident and the database updates apply whatever updates they need without a hitch. Every now and then, however, I will come across a project that hasn't received updates in a while, which means there are a lot of database updates to run through.
Having Drupal run 100+ database updates across modules and core can be a bit problematic. Some modules will require core updates to happen first, and when this happens out of order the database update update fails spectacularly.