Axel Alonso, aside from having the coolest name in comic book history, has been a mixed bag of an editor. He took over the X-books when Mike Marts left, which was pretty much at the start of Decimation. So we can thank Alonso for approving some really cool stories and crossovers like Messiah CompleX, the Utopia crossover, the move to California and restructuring of the X-Men as San Francisco's premier superhero team, the relaunch of New Mutants, the relaunch of X-Factor, Chris Claremont being shoved into writing only alternate universes, the upcoming Necrosha which should boost the mutant population a little, and all the other good stuff that the X-writers were allowed to churn out these past couple of years.
On the other hand, Alonso can't maintain a status quo for more than a single year. The X-Men opened Graymalkin Industries in the summer of 2008, and they've moved to Utopia in the summer of 2009. Alonso also dropped the ball on the Phoenix ___song Trilogy, hired Greg Land as a regular artist on Uncanny X-Men, and he dissolved the Red/Blue Team structure the X-Men have had since the 90's, which has recently resulted in everyone's favorite characters becoming extras for The Scott & Emma Show.
Still, I think the good has outweighed the bad. I'd be satisfied if the core X-titles adopted the Red/Blue format again, but apparently no one at the X-Offices wants that right now.