I think the purpose of why I use each is very different. For me, Voxer is more of a tool for a conversational dialogue with a small group of educators from Minnesota, Iowa, and Canada where we share the educational endeavors that we're currently engaged with in our respective positions. Twitter is much more of a consumption-based tool for me as I connect with and learn from a broader group of colleagues, friends, educators, and like-minded individuals who represent a variety of careers and interests as well as geographic locations. Blogger is my content sharing tool of choice as well as a forum for reflective thought around improving my own practice as well as sharing resources with others.
As a Connected Educator, I don't think that one tool is better than the others as they are all different and allow me to connect with and reach different groups and audiences for different purposes.
So while I may have been sharing and connecting more via Twitter and Voxer lately, Blogger is still a critical tool for me as it allows me to tie together not only my thinking but resources that I would like to share with others.