Can you miss out or overlook good strategies by using genetic optimization VS Full slow algorithm

Recently I've been doing a lot of   genetic optimization backtesting and I had a question for you guys. Does it pay, or is it worth it, to use the slow complete algorithm VS Genetic optimization? Am I missing possible strategies by using the fast vs slow? 
Yes, this can happen.

It depends very much ion the optimized parameters and the selection of the "fitness function".