hmm, the benefit of vegging longer is that your plant can bulk up. applying methods like fimming and supercropping (my fav) will increase your yield too, but require longer veg cycles.
vegging quick and throwing into flower is a quick way to grow bud.
other factors are also a consideration...if lighting is a problem, an even canopy would be better -- so as to localize your light, rather than the bottom portions dying -- or you can clip it off and simulate a sog with the plant...
essentially, the longer in veg, the more bud you get.
but certain strains autoflower, so they do their own thing.