Magnus: Robot Fighter has been pretty good -- there's an interesting twist which pushes the whole scenario in a different direction. I've really enjoyed it.
Justice Inc has been okay as a sort of follow up to the "Masks" and "Dark Knights: Shadow/Green Hornet" minis. I don't fully care for the portrayal of Doc Savage in it, but it's had some really outstanding artwork.
I'm enjoying Magnus. There's some great and interesting stuff going on in it. As a revamp of the concept, they have added some surprising depth to the idea and managed to get more mileage from their set-up than I would think.
Justice, Inc is pretty much crap if you care a whit about The Avenger, Richard Henry Benson. Like most of the "team up" books at Dynamite, this is a team-up of the characters in name only as they fundamentally change the back story to at least one of the characters. I thought Uslan's writing on the Shadow and Green Hornet team-up was above average. And, he wrote the 1970s team-up between the Avenger and the Shadow which is one of my favorite single issue comics. Here, he recycles some plot ideas from that (mind controlled agents/aides to turn traitor) and completely re-writes the origin of the Avenger, one of the few pulp heroes whose origin story unfolds live for the readers, and makes the character a second banana in his own story. It's also chock full of meta references that are more annoying than anything else. Everyone reading this mini should go and get one of the reprints of the first Avenger pulp story titled "Justice, Inc" and see just how far apart the portrayals of the characters are (and possibly track down one of the issues of The Shadow featuring Dr. Mocquino and the two Doc Savage stories featuring John Sunlight).