As far as some one receiving programming from dish their is no difference.From an
installer point of view when installing a dual tuner rec(322,522,625,921,etc)you have to run 2 lines from the dish to the receiver when using dish pro.When using dish pro plus you only have to run 1 line from dish to receiver and use a separator(special splitter).You still have to run 1 line for tv 2 for either one used or use diplexers.Also dish pro only uses around 200ma where the dish pro plus uses around 500ma