a lot of things depend on your question. how much room you have, how big are those pots, what type of strain this is, and pretty much your personal preference. depending on how much room you have i would defiantly let them grow a bit bigger and cut back on the topping. your plants look very nice and healthy, ready to provide you with some nice cola's. if heights goin to be an issue strap those branches down and you'll have beautiful bushy plants. remember that the longer the veg the bigger the bud, as hard as it is to wait its worth it. again other things need to be factored in as well like those pots. if you were to bump up their pot size wait for them to grow and get a good 12 to 24 inches...well you get my drift. basically, wait until you can't anymore: ) have fun!!