The first and third video weren't available in my country (damn youtube!) but I listened to the other two and I have to say she really has a great voice, her tone has great depth.
I do agree with some of you who say that sometimes Lisa's music and singing lack passion. I haven't had the pleasure of seeing her live yet but of course I know the youtube vids of her performances and I often think that she is a lot more versatile and daring live on stage than on the album. When Sea Sew had just come out I thought that maybe it's just her shyness and that she only needed to get used to being a solo artist but the soft and quiet singing really seems to be her "studio style"...
Then again, we haven't heard that much of the new album yet and maybe there are a few surprises coming our way!