I've used pretty much all incarnations of NavNGo products. From Amigo, iGO8, Primo and now NextGen. Each are designed for the tech of their era. I've seen Amigo on 64MB WinCE running better than NextGen on dual-core android phone. It's the skin that makes all of the versions great. NextGen is still young, only time will tell. Currently I do not see any benefit of replacing Primo+skin with NextGen, but it might changed in the future.