Come on, liking Staind is completely different than liking Flyleaf. I can't even get through the first millisecond of a Staind song. The connective thread is maybe the "Christian" feel to the lyrics but the vocal and even the music are completely different. If we're just going by the vocal, the guy from Staind has an AWFUL voice, the girl from Flyleaf (Lacey) actually has a decent voice.
It kinda reads that you're saying all Christian-esque bands sound the same, which is like when people come on here and compare every female fronted band to Paramore... side note, I'm not religious by any stretch of the imagination, just hate inaccurate comparisons.
The band is a nu metal woman fronted group. Nothing to do with religion, I just think the sound is outdated (as outdated as ska) and pretty bad. I listened to them once and it sounded like a female version of Korn. lol.