The excess weight of bigger rings saps the power of the rod. A rod of zero mass would put all the casting force into accelerating the lead. Increase the weight of the rod and its components and more force goes into accelerating the rod, and less into casting the weight. Excess ring weight makes a light crisp blank feel sloppy. Small ring weight changes have dramatic effects on feel.
Bigger rings means stiffer rings.
The stiff frames can effect the rod flexing and even damage the wall of a lightweight blank. The New Guide Concept favours smaller butt rings and more and smaller intermediates. The New Guide Concept ring spacings are closer to what I favour, but a little different to current fashion. Below is a chart which shows some tests they have carried out. Click to enlarge.