Segura's power will regress for sure, but I've watched enough of him to be sold on him being better than Aybar.
He's got comparable speed/defense with a much better approach at the plate.
Jean Segura = 1.5 fWAR in April (.367/.418/.567)
Mike Trout + Albert Pujols + Josh Hamilton + Peter Bourjos + Howie Kendrick + Erick Aybar + Alberto Callaspo + Chris Iannetta = 1.4 fWAR in April