The 0-60 time is still used. This is from current page on the official site.Just got back from the world. I have ridden RNR Coaster several times and it seemed like has slowed down. Has anyone else noticed this?
I notice they don't advertise the 0-60 in 2.8 seconds anymore.
Each "car" is furnished with a 125 speaker, 24 sub-woofer, 32,000 watt, onboard audio system—built to blast. Careen through the neon-filled streets of Tinseltown, the rock 'n' roll adrenaline pumping through your veins, your body feeling the force from launch to loop at zero to 60 miles per hour in 2.8 seconds. This is one limo ride you'll always remember!
http://disneyworld.disney.go.com/parks/hollywood-studios/attractions/rock-n-roller-coaster-starring-aerosmith/
In regards to the speed being different....Humans are notoriously bad at accurately judging speed, g-forces, etc. When you also figure in how poor our memories are the probability of your memory being incorrect is much greater than the ride changing. Our brains work more like a schizophrenic with a sketch pad and bad hand writing than a hard drive. Lastly the experience on any roller coaster will vary based on where you sit. While every car in the train is moving at the same speed the g-forces on each seat are different. In most cases a seat at the front of the train will produce a milder ride than a seat in the back.