> FP is great for many little things you might have to do. But for larger architectural considerations, I still find notable advantages to creating custom classes that have their own public API, private internal implementation, and that manage their state internally.

In OCaml, you usually do that with modules. For instance, you can easily write mutable or immutable datatypes that hide their internal representation.

> My favorite language for blending these techniques has become C++

I also like programming languages that embrace several paradigms. The problem with C++ is that it's a very complex language. Compared to C++, OCaml is a piece of cake.