I've been writing a scientific simulation in Fortran for half a year now. I usually like to write in some combination of C and Python.
While Fortran does make the life of a compiler writer easier, I think C benefits from being a small and very popular language.
C compilers are just more advanced, which gives it the speed advantage. But the speed difference for most purposes is negligible.
Choosing the right algorithm and approximations is a much more important concern (factors of 10-100-1000 vs. 1.1-1.2-1.3).
Dynamic memory management is not much different from C.
In my experience, Fortran is extremely useful for expressing linear algebra, which is heavily used in quantum mechanics.
At least it is much much better than C. So in terms of programmer efficiency in scientific calculations, I think Fortran beats C by quite a margin.
Fortran sucks at pretty much anything else though. For example, I think it's a lot easier to have a config module (e.g. class) to manage simulation parameters and recompile the whole application every time you change settings than it is to use an actual configuration file.
The next time I write a scientific application, I think I will have Python handle the logistics (parallelization, files, user input, etc.) and let Fortran do the (heavy) computations.