We have a set for our 7120 set for wheat.
Here's a decent generic picture of what the modules look like:
http://www.farmshow.com/images/resize.php?w=300&img=/images/articles/36/2/5346_l.jpg
Basically each concave frame is about half the width of the factory one, and consist of little square modules that you can put in whatever modules you need. I ordered a wheat set last year. Looks kind of like a red version of what's in the picture there, but not so many blanks. I never could get a real good test of them because lately wheat has been so easy to thresh and clean that I couldn't tell the difference between stock concaves and the sunnybrook ones. No whitecaps from either one! But I feel the sunnybrook ones should work better in hard thresh conditions.
As far as the weight of the concaves go, each half sunnybrook concave section weighs as much as an entire OEM Case module (flagship series). So if you have two halves bolted together to make a single unit, it's pretty heavy. Individually they aren't too bad though.
We haven't bought a second set for the other combine yet until we get some normal hard-thresh wheat conditions to really prove their worth!