I have implemented a locationlistener in my app which uses the Network Provider.
This all works fine because i want a location quickly and with GPS Provider it takes
Ideally, if you are not concerned on the battery usage, then it perfectly fine to use both providers. As Daren explained, you can filters the coordinates by using getProvider() and getAccuracy().
http://blog.shinetech.com/2011/10/14/a-good-look-at-android-location-data/