Some "cons" as I see it...
We don't have face to face interaction and therefore subtle visual clues are absent and the meaning of the post may be misunderstood.
It can get a little addicting in and of itself.
It doesn't get people outside their comfort zone as much as face to face support and for that reason may not allow for the kind of growth that comes from real interpersonal interaction.
It does not allow for the type of service that true service commitments do... driving people to meetings, taking meetings to others (prisons) or just going early to make coffee and talk face to face with others.
These "cons" are really not important to me, because, as I mentioned, I also attend AA.
Mark