Parts. Three Bricks.
Build. Here's the reason I bought this set. as you can see in the picture on the left, System Bricks can attach to the studs on Duplo Bricks. This gives us a base to build pieces of Terrain or Cover using a lesser amount of pieces. The hill in the picture on the right will take 1 Hit before being reduced under the Height Limit for Cover and 3 Hits before being destroyed.
Can you build something -- a frame, station, or starship -- right away? No. (-5)
Is it below, at, or above the golden ratio? Above. (-10) (The Golden Ratio is $0.10 per part.)
If you can't build a frame right away, or choose not to, does it have parts you should be able to put into use right away? Yes. (+5)
Does it have more than a handful of immediately useful parts? No. (-5)
Score: -15 (C). Scoring this set isn't really fair. This review was done more as a way to inform people of the compatibility between System and Duplo Bricks.