as i mentioned above, i only realize the iPad 3 hiccups because i am used to the fluidity of the iPad 2 that i used to own. i always experience hiccups when playing Metal Storm where it's either an actual motion hiccup or the motion crawls then picks up again (after firing a missile, the smoke trail skips outwards instead of flowing outwards like on the iPad 2). all of the iPad 3's that i have owned have done this (i exchanged two iPad 3's before i got one without backlight bleed and pink tint). the iPad 3 also hiccups when scrolling on a graphics intensive web page, something the iPad 2 never did. i know the retina screen requires a lot of graphics processing, but the A5X barely keeps up and is not sufficient if the fluidity of the iPad 2 is benchmarked as the golden standard.
i'm not the only one who feels this way, also real world tests have proven that the iPad 2 actually loads web pages more quickly and performs tasks in a more snappy fashion. the A5X revision (from the A5) was solely just to handle the retina screen which in my opinion it handles very well...just doesn't leave much wiggle room for anything else
I came from a original iPad to the 3, I've honestly never used a 2 for much more than a few minutes at a time. Maybe this is why I don't see it as vividly as you do.