Indeed, speaking as someone wholly unfamiliar with MtG, the book quickly made me fall in love with the factions.

But I have to partially disagree with you about alignment. While I can see half the factions being easily portrayed in either a positive or a negative light (Azorius, Boros, Izzet, Selesnya, and Simic), I think that giving a heroic interpretation to the other half would require some seriously twisty loop-de-loops or a full rewrite (Dimir, Golgari, Gruul, Orzhov, and Rakdos). Yes, some of them are very important to the survival of the city, and may count some good people among their members, but they are utterly corrupt organizations.