IGO8 is different than Primo. Whether it's better or not depends on what your looking for in a nav app. The best place to start is with a decision to make an effort to find out what these gps apps are all about. Then do a lot of reading.
iGO8.3.4 is a better more stable prog in my mind. GJ skin turns it into a very nice unit. A lot of people seem to be getting issues esp with memory with Primo d/l's.
May be lucky.
Down load both and give them a run. Maps etc are the same for both.