Workflow Field Update & Calculation Fields - overlapping functionality?

Workflow Field Update & Calculation Fields - overlapping functionality?

Hello,

Just curious, please clarify:

I know that the Enterprise edition had the ability to update a field through the Workflow field update feature. But recently you added calculation fields functionality (available in Professional edition and up) (Thank goodness! finally! it opens up a whole world of possibilities - I have been craving for that feature for a long time!). My question is aren't these features overlapping in functionality? Meaning can't one achieve the same effect through calculation fields, what otherwise was achieved through the previous field update feature? Does it make WF Field Update feature moot? 

I am also noticing that your feature list / editions comparison list  has not been updated to include the calculation fields feature. In fact, I accidentally stumbled upon that feature when I clicked on "What's New?" Why isn't this being put in bold letters in the front page of ZohoCRM? :o) This is huge! - Thanks!