i use sygic 10 and rarely have an issue with it, the routing is good and having offline mapping with turn by turn voice guided directions is great. I also have no issues with it in pr1.3, great product wish you got access to all maps for a flat fee though, that is the only downside for me...

Other than sygic i also use geeps, mappero and gloudgps - my favorite out of them would be geeps, all have the disadvantage of needing to be online though which is not a problem most of the time...