Yeah, I've got to agree here. The problem with constructs like generics and co/contravariance is that they can (not will, but can) make code very hard to read,

Yeah, I've got to agree here. The problem with constructs like generics and co/contravariance is that they can (not will, but can) make code very hard to read, so you start to lose the ability to completely understand your code as you're scanning it with your eyes, whereas a situation where a class instance is simply being "re-cast" from an ancestor type to a descendant type to "help" the compiler is very easy to understand (although, I would definitely recommend a healthy dose of comments around such code). And, as you say, you can always use a run-time "is-a" check to make sure that you properly handle any violations at run-time that could bring the whole application down. Of course, there are different metrics for different types of applications, and I'm sure that there are applications that need this level of type soundness as a matter of safety. However, I would surmise that most LOB applications are primarily interested in coding productivity and, as you say, these types of issues start to work against that productivity past a certain point.