I just graduated from the Main Campus TSU ADN program and it prepared me well for the boards. I passed the 1st time, with 75 questions (the minimum to take) in less than 1.5 hrs. I was not an exception. The pass rate should be much higher for this year's class because I don't know of 1 person in my class that has failed. I believe most have taken boards as well. I have a Bachelor's from a Big 10 school, for my previous career, and am not ashamed of attending TSU after all. I believe that those folks that failed the boards the 1st time at TSU were ones that either took boards right after graduating (without doing the studying necessary) or they waited too long after graduation (like the Fall) to take boards.
As for the "quality of students" at TSU, the students are just like anyone else in Middle TN. Honestly, TSU students are actually probably better prepared for various situations because their labs aren't extremely high-end and don't baby the nursing students. But, the students are still well prepared, from clinical experiences. TSU's standards are the same as other schools in the areas, when it comes to acceptance requirements. In fact, several classmates had 3.9 or 4.0 GPAs (and they were transfer students into TSU). I was personally accepted at Aquinas (only applied to TSU/Aquinas), but chose to go to TSU because of the $. Don't listen to rumors about a school...only go off of 1st-person accounts.
While nursing school is to help prepare you for boards and to be a safe nurse, you are ultimately responsible for passing boards the 1st time.
Good luck and let me know if you have further questions.