Ok I have a question about switching over to virgin mobile?

Is the virgin mobile coverage and network good? its supposed to have sprint's network right? is Sprint's network even good? Last, would you buy the Samsung galaxy ring or the LG Optimus f3 4g? their both almost the same but not quite and the reviews have them neck in neck except for the front camera which I plan on using a lot probably !. and I think I read one of em is bad and repeatedly shuts off :( please help anyone ?