That would totally depend on how well the herb the seed came from was grown. If it was grown very well you will not be able to top it. If it was grown poorly, and it's genetics are better than the final results were, you will end up with something at least slightly better.
Every stain has it's' genetic limits and nothing anyone can do will be able to make it better than it's genetic limits will allow. The very most any grower can do is max out what the strains genetics can give them, and I would say that few do that.