It's been a while since Marvel published a "What If...?" comic, but now that the idea's been brought back, the publisher isn't doing it by halves. "What If? AvX" #1 by Jimmy Palmiotti and Jorge Molina is a four-issue mini that re-imagines the entire "Avengers Vs. X-Men" crossover. It's a possible opportunity for readers who didn't like it the first time to give it a second chance.
To be fair, those readers probably won't. Marvel's "What If...?" comics are always at their strongest when concentrating heavily on the one-line premise for the story. Unfortunately that's where "What If? AvX" is at its most deficient. The pitch of the story, such that there is one, appears to be, "What if AvX happened slightly differently for no particular reason?" Focused is not a good descriptor for this series.
The differences in the story's execution are minor but arbitrary: a different team of Avengers flies into space to confront the Phoenix. The X-Men attack the Helicarrier rather than wait for the Avengers to invade Utopia. Magneto's role in the story is magnified. But there's no obvious inciting moment for these changes, which dilutes the very point of the story. It's not so much a "What if...?" as a "Why not?"
Beyond that, it's as technically competent as one would expect a comic from seasoned pros to be. Palmiotti and Molina know what they're doing and dutifully lay down the story tracks. Writing a summer crossover can be a thankless chore, and writing an alternate-universe version of it is probably a little more enjoyable in that it frees the creators from scrutiny. At the same time, there's not a lot of room for individual expression when re-treading other people's scenes.
The lack of space caused by mashing several issues into one leaves the story feeling a little rushed, but fans know the beats already, so it isn't a huge problem that the creators don't show a lot of connecting moments. Palmiotti has clearly chosen to focus on the relationship between Magneto and Hope, and their scenes together are some of the best -- but then, who doesn't love a philosophical brutal Magneto?
As for the issue's attempt to incite a desire to return for more, close readers will see that there's potentially a little more going on than the page makes explicit, but it's still in typical "What If...?" territory: unexpected deaths, things going rapidly awry, but no particular point to make -- at least, not yet. A 4-issue series means there's the potential for a closer examination of the themes and ideas than the average one-issue cover version can manage, but let's face it: like all "What If...?" stories, it's a novelty at best.