Being a Batman geek, it doesn't take long to love Harley Quinn. One thing I love about this comic is that you can hear Arleen Sorkin's voice coming out of every one of Harley's speech bubbles. Not that Ivy and Catwoman aren't lovable and dangerous) too. This gives you some nice up-close-and-personal relationships with all three women, along with a section focusing on a Batman (Nightwing)/Riddler team-up. With everyone else in the Batverse going to hell with their lives, it's nice to see the, by comparison, relaxed lives of the ladies as they make their own headquarters.
Paul Dini's writing is great, of course, and nobody understands Harley like her creator. And some of the lines, like Harley's "A lot of crazy thoughts go through your head just as you're about to be stabbed to death by an angry dwarf." and the "Joker"'s "Shh! Be vewy, vewy quiet. I'm hunting wascawwy wenches.", are just precious. Not to mention the fact that we finally get to see Harley's family. The "Gaggy" storyline seemed a bit odd at first, but I looked it up, and the guy really did exist way back in the early comics age, so I guess it works.
I wasn't quite sure about Guillem March's art at first, being used to Jim Lee's work on Hush, but I'm adjusting to it. You gotta love a lot of his expressions, especially. Ivy's innocent expression when admitting that she gave away thirty million dollars to charity, and Harley's ecstasy upon seeing her neice and nephew ("HI, MONKEYS!") are fantastic.
If you find that Batman's villains actually more interesting than the caped crusader himself, I'd call this a must-buy.