Looking at the buzz these days, for management of larger/multiple sites, Drupal seems to be the strongest contender on the open source front. How does Drupal stack up against the big-name commercial CMS (Fatwire etc.)?

One answer could be that commercial CMS offerings provide dedicated support, but that really seems to be a non-issue to me - there are many companies that provide support for Drupal.

I will be playing with demos to assess performance and usability, but does anyone have any advice on what I should look for?