Have you tried out using an external monitor?
This laptop I use is also recent I got it in December. It's an HP 2000 Notebook with an HD screen. The specs are better than my old laptop which ran FFR great. For some reason the new laptop was consistently choppy no matter what the fps was but ffr was playable. Any other rhythm or flash game is 100% smooth.
One night I sat on the lid cracking the screen horribly and had to plug in an external monitor to use the laptop. The external monitor did not lag at all, the game looked 100% smooth with r^3 set to 80fps. Later my sister gave me a newer lcd monitor and the game chopped just as much as the laptop's screen. I tried external hdmi to TV out and that was the worst. 3 out of 4 screens I tried sucked ass for r^3. The monitor that didn't is an old CRT Monitor made by eMachines model 17f3 that we've had since 2003.