I know oversize irons have a larger sweet spot, but is there a disadvantage to oversize for shots from the rough?
The larger the frontal area you try to push through the rough the harder it’s going to be. Nevertheless, because oversize irons aren’t much bigger than traditional-size models, you shouldn’t be too concerned. That’s because the potential benefits of having a set of irons with a slightly larger sweet spot outweigh the extra drag you may experience when hitting from the rough.
Obviously, the best advice is to be in the fairway rather than the rough. For more advice about golf equipment, read my Simple Rules for Buying Golf Equipment.