I brew Gluten Free because I am celiac and if you don't use Maltodextrin the head is terrible, one thing you don't ever want in your life is bad head. Around 90% of the recipes that I have made called for 8oz of maltodextrin at 5 min remaining, the stuff takes some time to blend into the wort, but if you are brewing gluten free it is pretty much essential as sanitation. I use it in my 5 gallon size brews, but then again, this is gluten free so for the "normal" people out there a little less might be ok. Further, only 5% of Maltodextrin is fermentable so I suppose it doesn't matter too much, it also adds a little extra solids in the yeast cake during fermentation (just an FYI).