I use about 70% drags, maybe more.  In my country I like at least 8' of chain and I make my drags of 1/2 rd stock.  My poit is, that the exact specifics of your set up will largely be determined by the terrain and vegatation.   The longer chain gives you more hangups which makes tracking a bit easier and wears the critter down more.  Also, I do not like twin toop chain on my drags, I perfer the heavier 5mm too #2 welded link.