I would say it also depends on how your surgery goes. I found it much faster/easier to simply drink out of a cup but I only had my lower done and just a splint. Their jaw bra worked very nicely and much better than the one provided to my at the hospital.
I am ordering mine this week as well. I plan on getting the hospital pack and the wrap around your head thingy. I think any more bags would be overkill - from what I see here most people only need them for the first few days.