i top mine...all of them, always have and always will.

only pinched once and only early when they're seedlings. i take the top off when they're at the the 4th node (iow, 4th node comes off leaving the 3rd as the top) so the split is low and easier to train the almost 2 separate bushes ya get from it. colas are still as they would have been if left alone because recovery time is nearly as long as their vegging time. this pinch makes it easy to train the trunks to grow horizontal 8"-1' off the ground in separate directions and makes for a shitload of long cola's!

topping/pinching them close to harvest will affect the yield and you won't be happy...they need at least a month to 6 weeks before flowering to fully recover.