For my Master's thesis, I couldn't get satisfactory results with a genetic algorithm, even after spending quite some time tweaking the parameters from the default. But, with the default parameters of the simulated annealing code, I got some excellent results. For a few cases, I managed to get my model to fit almost perfectly with the experiment. For those cases, the only spots it didn't fit were parts where the experimental apparatus wasn't characterized well.

So, it's highly problem dependent.