So I don't know anything about South, but I can give you some details about Lipscomb and Belmont.
I would say they are pretty similar in how well they teach. I'm about to graduate from Belmont and during my APPEs I spent time with various Lipscomb P4s. I would say the knowledge/skill base was equal.
I know that Lipscomb does block exams, so every class you have you'll take an exam at the same time as every other class. Belmont doesn't do this. If this is a pro/con for you there ya go.
Lipscomb is more religious than Belmont. While both have some religious aspects to them, at Belmont this is mostly for the Undergraduates and does not really exist in the pharmacy program. My understanding is that it is more pervasive in the Lipscomb program, but still not as bad as their undergrad. Again, if this is a pro/con for you there ya go.
Those were the two things that stood out in my mind the most about the two schools. If you want more specific info about Belmont, PM me and I'll see what I can do for ya.