Unitedstreaming Vs Unitedstreaming Plus

In trying to determin if the district would get their money's worth of usage and material by going completely to Unitedstreaming plus, I asked teachers to preview the site and provide feedback. What I found out, not necessarily to my surprise, is that my high school teachers responded to me quicker and in larger numbers. The teachers that did spend the most time evaluating the website were science related teachers. They found that the options doubled in number when looking into Unitedstreaming Plus. I found that the options for many topics related to the science field did increase. I also found additional options for my Spanish language instructor.
However, I am still not sold on purchasing the "Plus" for all schools in the district. I would like feedback from teacher, administrators, and integration specialists that are using the "Plus" option for grades K-8. Please let me know your thoughts.