The reputable cab companies do cost (roughly) twice as much as a cab hailed on the street. I have never had a problem with street cabs, but out of personal preference I always call a company when I'm travelling with valuables (my luggage, passport etc). While most drivers seem perfectly honest, why risk a random cab to save just a few soles? As far as La Rosa Nautica goes, if you've never dined and had waves crashing into the windows before, then you will enjoy the experience, regardless of what you think of the food.