Shared blog vs. aggregation of personal blogs: Discuss.

Here is my predicament; it may be that of other bloggers: I am already maintaining two blogs; one on personal thoughts and interests, another on IT (like this one). Although they are all on blogger (by co-incidence), I want to use different usernames and names on each and hide some details from some. I already aggregate other blogs, some of them from members of this one but on other sites. It would be easier for me to see all the entries into this blog through my global aggregation, in which case sharing of a blog adds no value to what I would get by aggregating individual blogs. So, given the ease of feeds and aggregation, is it meaningful to share a blog as we do here? Where are the flaws in my argument?