Yes I would recommend getting as close as possible to that genetic max. WIth all of our bodies being different its hard to judge who can keep those extra pounds over genetic max and who cant. Like the post above 10-15 is realistic but beyond that, who knows.
Like Stevesmi stated your genetic max just means you have dedicated yourself enough to that point that you have "earned" the right so to speak to artifically inhance your bodies limits. There is really no sense using roids prematurely. Its a waste of gear and money, the body is an amazing thing and its extremely receptive to good food and hard work especially newbies and people willing to put the effort in.