Purely theoretical match-up here (ignore the obvious politics and loyalties.)
Let's say GSP beats Hendriks whilst Rory McDonald beats Penn and then Hendriks setting himself up for the titleshot.
Who takes it? Is Rory basically GSP 2.0 or is there something that separates the two? 
GSP is better everywhere.
If I could have one wish come true this year, it would be BJ's prediction that he will beat Rory so bad it will derail Rory's career. I hope BJ sends this kid back to Canada questioning EVERYTHING and in need of a fucking shrink to deal with the psychological trauma.
But that's just me. Wouldn't want to see the kid permanently injured or anything.
GSP has the big brother kicks the shit out of his little brother mental edge. If they didn't know each other....who knows...
Help me out - why all the furious Rory hate? Is it just because he's been bickering with BJ or was this a ore-existing thing?
Raezor19 -FinestScotch -Rory has more pure power, GSP is better technically, at this point. And it's not close.
Actually, Rory"s fights now at 21, 22 years old look very similar to GSP's TKO fights when he was 21, 22....
Difference is gsp since then has been putting on clinics vs the best fighters in the world.
I think the difference would be the consistant pressure gsp would put on Rory and how high quality it is. 
The only way for Rory to prove that he's better than GSP is if he beat (and finishes) BJ in less than 3 rounds which I think he will accomplish easily.
Gino_Corona -The only way for Rory to prove that he's better than GSP is if he beat (and finishes) BJ in less than 3 rounds which I think he will accomplish easily.
That wouldn't prove he is better than GSP.
Bucephalus - If I could have one wish come true this year, it would be BJ's prediction that he will beat Rory so bad it will derail Rory's career. I hope BJ sends this kid back to Canada questioning EVERYTHING and in need of a fucking shrink to deal with the psychological trauma.
But that's just me. Wouldn't want to see the kid permanently injured or anything.
Gsp sought the same sports psychoologist gonzaga had after serra knocked him out.
My opinion is that Rory trains like GSP does without understanding why GSP set himself up with Firas, Danaher and Jackson. GSP is the scientist, the quintessential martial artist on the quest to improve himself. Rory is a physically gifted athlete but I don't think he could have achieved what GSP has given similar circumstances.
If they were to fight, it would be GSP's toughest fight yet because his physicality is matched, but I think GSP has the better mind and is more technical than Rory at this stage of his career. So no, I don't believe Rory is GSP 2.0. I think Rory trains like GSP and is younger, but GSP's intelligence and mental game sets him apart.