It was me who said it
but things have been changed, so its around 50/50 now
earlier, if you leveled fast enough you didnt need to train, cause levels made stats better. And ontop of that you got more AP more EP to level faster. So instead of training on level 15, you could powerlevel to level 20 and train there. Since EP regen rate is higher and you can do bigger trains, meaning shorter tim to train and you can get back to power leveling again faster, without losing the advantage.
2 people on level 15, one is training and one is powerleveling. the one power leveling to level 20 will start to train there and will train while he waits for the other level 15 to reach level 20. The one that reach level 20 first will have MUCH better stats. This cant be applied to AWA since we have joined at difference point, but it is a valid point nevertheless.
But some changes has been made, higher Happiness refresh, battle modifications making skills more important and I think that level importance has been cut back.
I still think that levels are important, they give bigger trains and recharges EP faster.