After using my Note 2 for a while I have to retract this statement, there is definitely some lag. One glaring example is in the phone app, removing the phone from your ear and it takes a second or three for the phone to turn back on. Also switching the phone apps tabs at times takes a second or three, at times the screen flashes like its being redrawn, other times it just lags, and occasionally it runs smoothly.
Its not always though, sometimes the phone runs very smoothly, but at other times there is a noticeable lag, I'd say a good 1 to 3 seconds, worse in some cases. For example opening or even task switching to the Data Usage program can be a mind numbing 4 to 5 seconds for it to open up.