Cardio is the only so-so weakness I see in Aldo's whole game. Him and GSP are the best if I look at it like that.
I think Aldo will shoot in this like he did vs Hominick, also because he should have the edge on the ground and that Guida fight wasn't a good one by Pettis.
I'd compare Pettis to a more versatile, flashy version of Lyoto on the feet, while I'd say Aldo is a combo of Anderson and prime Shogun there. Am not saying Lyoto's a better striker than Silva, but that Pettis' added elements make it tough for Aldo to let that power shine, mainly in low kicks.
Of all the LW's, a view Pettis as the toughest fight for Aldo, but still think this is a toss-up. Am also biased towards Pettis, but trying to be objective I think this will go to a decision and Aldo's effectiveness in takedowns and his top game from there will decide if he wins or loses.
The weight cut for Pettis is another thing. He's not a big LW, but also not a Edgar or Penn - he could have trouble with it, and he needs cardio to take this. If that goes well, he should get the better of Aldo standing, but not by a landslide.
It's, imo, a harder fight for Pettis than Bendo would've been. Close, will need to watch their fights to maybe be more clear.