The only time i wouldnt top is in the SOG style. This is just to make fuck off big colas like Dr.BudGreenGenes does. Check him out, he's awesome!
I hope I topped in the correct place I pinched off the top hopefully I didn't screw-up.
Veg for as long as it takes to fill all the area of the screen with the plant. Then flip to 12/12 and you will make the most out of it. May take a little longer veg time but will be well worth the wait. Once the main stems have covered the entire screen (under side of screen), the many side shoots will grow vertically into many nice colas once flowering is induced.Yeah I want to put the screen on at about 10", then veg for another three or four weeks.
I have had this same question, a lil trial and error, and found that topping isn't the best, in my quest I found out that Supercropping, is the answer for any problem. If you have height, space, or jus want control of things, go with supercropping.
When I used to top I would get, for example, 2 oz per plant. Now with doing supercropping, I'm getn more than 3-3.5 oz per plant. I have tried this on several strains, and some do jus prefer topping, or jus being left alone to do it's thing.
If have any questions on supercropping, jus ask around, or look around in here.. There is alot of info on it. Good luck, man.