If your lv is downscaled, you'll loose lots of str for example, and your damage will go down anyways.
and probably you'll be subject to *optimal lv* restrictions, loosing stat boosts/def/damage from equips too.
So you might wanna use some equipment in lv range of content for such. Or hopefully def/dam of wep/armor wont drop so much that they become worse than lower lv gear.