Transitioning from WordPress to Drupal (Designers)

For those of us quite familiar with WordPress, but also aware of its limitations, looking to work more with Drupal. Learning similarities and differences between the two working environments with compare and contrast would be most helpful. Some features are similar but have different names. Some features are different all together. Knowing where to start and what common ground there is between WP and Drupal and what big differences there are would be wonderful to hear from someone who has experience with both. I'm coming at this from a designer/themer perspective, so that would be most helpful for me personally.