The opinions of CEG'rs of "res/no res" seems to be about 50/50. IT is a definite difference in sound, a slightly deeper tone.. Not ricey, IMO, but deeper... However the preference seems to waiver, depending on what you want, sound or performance. Those on the opposite side of that 50/50 seem to side with the fact that there hasn't been any proven performance enhancements. Note: I said "PROVEN", not to be confused with "THERE ISN'T". There may very well be, though nobody has (To my knowledge) dyno'ed and posted.. Do you want sound, or are you more of a performance oriented individual? It is all a matter of taste, when it comes down to it..
Ray