They each have a good purpose, but if I had only one choice, then it would be the drag.
Here in MN the ground freezes early and pounding stakes gets difficult. At least with a stake it creates a catch circle after the first catch and this in itself is an excellent attractant for subsequent catches. Also, if you stake correctly, your catch will be right there and you won't have to search. The downside to that is your catch is in the wide open exposed to thieves or deer/bird hunters wanting to help you dispatch your catch using a 30-06 or 12ga with #6 shot at close range.(that sucks)
Now with drags when you catch something, the animal hopefully will get caught up a short distance away, but out of view from possible trap/fur thieves. Using drags also preserves that one location. I use them often for snaring at great locations. Snares work awesome in tight areas and if you stake a snare, that location will be trashed, but if you use a drag, the animal pulls the drag from there and tangles elsewhere. This way you can reset another snare at that location again!
Using drags are also much faster. Instead of pounding a stake, all you have to do is create your trap bed and sight/bait hole and lay the drag behind the set. I just throw some debris on the chain/drag and move on.
Some say drags are no good because they have lost an animal on a drag or it takes to long to find them after catch. Well, sometimes bad things happen, but most often it is the trapper's fault. The length of chain on the drag and the amount of trees/brush the catch can get tangled on determines how far it will travel before the drag catches on something. So if an area if full of smaller trees/brush, then then can get away with using shorter chains on their drags... and vice-versa if the area is thin of tangling material. The longer the chain, the likelier the catch will tangle faster and travel less.
iSnipe