I was left feeling a little unfulfilled with Ex-Purgatory as well. I mean, it was interesting enough I guess, but as you said, there isn't a lot of actual superhero vs. zombie stuff anymore, or expansion out into the rest of the world to keep it fresh. I like most of the characters well enough, but I need to see them do something different. This one was a little fun because you got to see a different side of the heroes, but I am ready for some bigger shit.
I guess I need to read the Milkweed stuff, I've seen enough mention of it. Finishing up the 3rd Grimnoir book right now, Warbound, and while I wasn't a huge fan of the setting at first, the books are really growing on me. Obviously I don't know how this one ends yet, but talk about upping the ante, he's definitely taken it the opposite direction that the Ex-Heroes guy has, and I like it.