I do agree with the "late-bloomers" idea.
They really do seem to just be growing a lot recently and getting better as well.
I mean look at the others, most groups/idols make an impact at debut and gradually fade off with time or if the impact didn't come at debut, they'll just die off real quick.
But with KARA, they've been through 2 major crisis now and just keep getting stronger.
As they say, whatever doesn't kill you just makes you stronger so I'm hoping to see more of them. =)