It really depends on how you evaluate them.
Roy is coming off an All Star season and a fat contract. Expectations are high for him, and they should be. He is going to continue to be the crux of our team, and our defense in particular. Roy locking down the paint and being a consistent threat on offense is what will make this machine work.
Paul George is coming off a second season where he started to get some attention. The Slam Dunk Contest and his huge 30 point game in Dallas, added to the tough defense he has earned a reputation for has all given Paul a name nationally. I think the expectations for this season are higher among Pacers fans than among the general NBA fan, but it's out there.
I think Roy continues the strong play we saw last year, and probably has a slight bump in stats based on increased minutes. Hopefully some more consistency and strength will be evident, but Roy is likely to stop improving so drastically and simply settle into his prime.
Paul should make a good jump based on his work, his focus, and his coaching. The stats will likely come and go still, as he's not going to be the likely focus of many gameplans. Our team's strength lies in the balance and the options we have, so we'll continue to see 10 point games followed by 20 point games. I think his average will go up and his defense hopefully remains rock solid, and maybe even improves in the few areas he struggled.
So from an improvement standpoint, Paul is likely to have the better season.
From a raw impact on the team, game, and NBA, Roy will still have the better season. If Paul even challenges Roy on the grander scale, the Pacers could beat Miami in the playoffs.