I've never done a side by side but IMO, all other things equal.. no. You just get less popcorn and a super sexy, even canopy.So a plant that is main lined does not produce anymore flowers to a plant that has not been main lined?
Better buds overall? yes.
More yield? possibly, but I really don't think so. It seems to me the weight is just more distributed between your colas. You have to take into account that mainlined plants are generally vegged longer than those that are not.. so.. Like I said, all other things being equal, I don't think so.