I love this type of portrayal of Severus; it falls more in line with canon Snape, and that's something that I don't think is explored enough in fic.
Writers tend to go for a more fanon approach (which I adore as well; really, I'll take Severus just about any way I can get him), and it's interesting when they use the darker side of his personality.
it always makes my day when you like one of my fics