I've recently gone through this song and dance.
Wheel set 1:
Chris King SS Hubs
DT Swiss Comp Spokes and brass nips
Velocity Blunt SS rims
Wheelset weighed 1685g with tape and stems according to my notes.
Wheel set 2:
Chris King SS Hubs
CX Ray spokes, alloy nips
Skyline rims
Wheelset weighs 1540gr IIRC with tape and stems
Wheel set 3:
DT Swiss 240S geared hubs
CX Ray spokes, alloy nips
Lightbikes Carbon Rims
Wheelset weighs 1570gr IIRC with tape and stems
The difference between the 1st and 2nd wheelset was noticeable for me, but that included going from a alloy rim to a carbon rim. Power delivery is better on the carbon rims due to the stiffness as well, and the bike is notably more responsive with the carbon wheelset on it. The difference between the 2nd and 3rd wheelset is a heavier rim offset by a lighter hub, so while the wheelset weights are pretty similar, the distribution of the weight in the wheel is different. That said, the difference between 2 and 3 is much less than the difference between 1 and 2.
TL;DR version
All else being the same, don't buy carbon specifically for the weight. Consider that a bonus. I didn't ride the Blunt SS wheels nearly as hard as the carbon ones simply because they were so fragile. With carbon I got the weight, stiffness and width I wanted without the fragility.