Great Jumping on Point
I've always enjoyed Irredeemable since it came out last summer, the concept of a godlike hero getting fed up with humanity despite what he does day in and day out and the reprocussions really tell a great story, and although the story maybe be a little cliche, the way the Plutonian, and the rest of story is written throughout the series so far makes it seem like a fresh concept.
Incorruptible on the other hand I had vaguely heard of but not read up until this point, I'll admit at first the story here also seems cliche, a Villain reforming to the side of good, but again the way Max Damage is portrayed and how quickly he undertakes the transformation was what really appealed to me. His character and style, along with that of Jailbait, are both very entertaining. I quickly looked up the back issues and read what had been released to date of this series.
I have to say I prefer Jean Diaz's art over Peter Krause's a tad but both are solid artists and the covers are equally amazing.
In short if you are a fan of Mark Waid or of either of these books, pick them up, a great jumping on point for either book, and if your comic book store limited how many of the Free Comics you could have (mine was 3) pick this one up, its a 2 for one deal.