Aldo. Pettis is a dynamic, fluid striker with great TDD and slick subs. Aldo is ever so slightly less flashy but significantly more technical in his striking, while still managing very impressive moves like flying knees and leaping off the cage, and has developed great boxing and an awesome offensive wrestling skill set to compliment his much better TDD and highly touted BJJ. Difference in speed would be negligible but Aldo backs it up with a lot more power.
Lately Aldo has been slowing down in the later rounds which is his biggest weakness IMO but if they were to fight I see two things going in Aldo's favor to seal the deal. First, the fight likely happens at 155 where the lesser weight cut helps Jose out immensely. Two, considering the striking pedigree of both fighters I highly doubt this goes the distance anyway.
Khabilov. Swanson. Bermudez. Gastelum.