Brett Manning and Singing Success are the same people (technically; same company). Melissa Cross helps out people in hard rock and metal mostly. If that's your style, great!
I don't know too much about the others...
Is 'Singing Success' really that bad of a program? I've been using it for a while, and it's pretty good.
Could I have your experiences?
I also have Eric Arseneaux's 'AAproach 2.0'. That gave me some fantastic breathing exercises.