Some do it, some don't, i do it sometimes, other times i don't, and i think germinating is helpfull if you have a hot soil and want the seedling to start up in a neutral environment with just the water.
If the soil is hot germinating goes a long way. If its not i think it will make at the most a 5% difference in plant aspect, making it larger i would say. But it really shouldn't make much of a difference, just do what you like the most, the method that sits with you better.