Imo Alice doesn't really work well, because both ways in which you could enjoy her storyline don't really work.
If you like corruption and seeing a character loosing their morals and inhibition to lust over time, then Alice has the problem that she doesn't have a clear defined character. At least imo. I never watched SAO, but Asuna, Liz, Suguha and Keiko (That was the name of Asuna's mom, right?) all have clear, easily understandable characters, morals and goals. So the prospect of seeing them get corrupted is interesting. Alice doesn't really have that much character, she's a cop and she's pretty nice, I guess. But that's not much of a character.
And if you like to see a character from another, IE see Alice get stolen from Klein. Then you have the problem that Klein and Alice aren't together. The game told us that they are somewhat at this point. But most of the game the only thing we see is Klein kind of pathetically lusting after Alice, without any serious chemistry between them. The game then tells us that they are getting close off screen, but that's not really effective in creating a believable relationship. Because the player doesn't see it.
The dev seems to have realised this though since we got the scene were Klein jumps in to save the cat in the previous update. Maybe he'll get there.
