I cannot sit on the fence. I like twitter and what it offers. I have learned things I never would, built genuine relationships with international people who I would have perhaps have only met over a quick coffee at a conference. And I have changed the way I speak about science.
This post by Mark Brandon sets out nine great reasons as to why he finds Twitter so useful, many of which relate to science communication.
I believe twitter is a strong positive for science, and it is a worthwhile investment of your time.
I completely agree with just about everything he has to say. It's a good list.