I'm a pretty nit-picky consumer and I'd say this is a good product. They're very easy to clean (no seams for food/debris to lodge into), which is very important to me. Plastic material is quite rigid and sturdy (I'm guessing polycarbonate). The magnetic handles are sufficient for keeping them together and organized in the drawer, but are not so strong that they're annoying to pull apart. However, when nested together in a stack, it looks like the stack is missing the 3/4 cup size--indeed it's not included.
It would be cool if the magnets were strong enough to stick the top face to a steel panel (like on the side of a refrigerator), but they're not--I tried it. They will attach to a metal surface using the bottom side of the handle, however (as the cantilevering from the oven back panel picture--I tried that too), but that's not a very practical storage place is it? I guess I'll just be keeping them in the drawer. Better that they're out of sight anyhow I guess.
The alternating colors help in putting them together in the proper order after cleaning all of them, but that's a pretty minor feature. I suppose they help select the size you want out of the stack once you associate the size with the color.
Incidentally, I bought the similar magnetic measuring spoons. I say the same for them as for the measuring cups.