It's been a while since I've used Homesite but if I remember correctly one distinct difference between the two was that you cannot edit in "design" mode in Homesite but you can in Dreamweaver. And if you're a beginner you may want the option to be able to edit in either mode. Homesite is often best for programmers because you always work directly in the code.

Of course it has been years since I've used Homesite so maybe it's changed.