I've never tried a scrog before but the biggest glaring con I can see is the fact that once it has been established you can't move your plants at all. That makes it harder to water plants behind them if you have a bigger tent or even just being able to easily see the backside to check for issues. It will also make defoliation more of a pain in the butt. I personally like to be able to take my plants out of the tent and give em a once over now and again. My training consists of manifolding the plants so that they grow nice and evenly in the first place. That way I don't need to worry about a scrog at all.