toping them would do good, toping usually starts very early on, to those trying to make a bush type of plant. but if you top now you could get better results, then if not topped. by topping your getting more cola and bud sites, so i say always top especially if you have the room. just remember to stop toping about a week or 2 before 12/12. here is a vid on toping, from a skilled grower.

YouTube - KoMA TOPS EM AGAIN!