Reading the Stahwlwille Catalog- I noticed a lot of their wrenches can be had in sets of organizational foam or plastic. What are the benefits of one over the other in a home garage toolbox? They both seem pretty slick.
I can't say specifically for Stahlwille, but my experience with foam vs. plastic modules is that the foam fit the wrenches, sockets, or whatever, tighter.
With the plastic modules the wrenches vibrate around when opening and closing box drawers.
The looser fit can also make it slightly easier to grab a wrench , etc.
The surface of the plastic can be easier to clean if necessary.
The main down side to the plastic is the modules seem to break easier.
If you have to carry the module in a portable case, individual items are more likely ounce out of their place.
Foam modules tend to be dual colored which makes it easier to see if somethings missing.