Props to D for having such a simple implementation of fexprs[1].

The downside compared to macros I think is that, as argument expressions become lambdas, it becomes harder to manipulate them. Check the cond example which needs two fexprs, whereas one macro could do it.

Not sure about D, but if it were lisp, even lambdas could be manipulated as lists. Macro args not having the lambda wrapping just seems simpler.

[1] https://en.wikipedia.org/wiki/Fexpr