Actually, I was thinking about these two the other day. They're very similar fighters, except for one very key difference.
Pettis covers up his relatively weak fundamentals with flashy techniques. McGregor covers up his very solid fundamentals with flashy techniques. They're both using smoke and mirrors when they throw their spinning shit, but for very different reasons. Pettis is trying to get a good looking KO and land something spectacular, because that's the only realistic way he wins (I'm not saying he's bad by any means, he's a great fighter- but his defence and basic strikes simply aren't on show). McGregor is trying to make you forget about how solid his basic striking is and bait you into making mistakes by throwing elaborate strikes that make you think he's open, when he's already waiting to hit your reaction.
If they fought each other I'd bet the house on McGregor. Pettis is tailor-made for him. RDA now... I'm not so sure.
I love watching Pettis fight, and will always tune in to see him, but let's not forget that he has had his weaknesses exposed on multiple occasions now. He's been soundly defeated by Guida, RDA and Alvarez, and was getting beaten soundly by Melendez too. Benson was outgrappling him before getting subbed. Pettis hasn't actually had enough dominating wins for the hype and accolades he still gets, he's way more similar to Uriah Hall than McGregor.
