I tend to use my companion to draw aggro and take hits; this is true of just about every Beth game where companions have been an option (although in Oblivion more often than not they resigned to 'torch carrier' due to poor AI). To this end, Skyrim's new companion command system has been quite allowing; I can tell my companion to run in and attack something with a few button presses.
Unfortunately, it's still not as streamlined as it COULD be. I'd like the ability to be able to map a companion command to a hotkey, so that all I have to do is look in the direction I want them to go and press a button for them to be off. I realize this is likely a job for SKSE but I thought I'd put the idea out there for anyone crafty enough to make it work in the eventuality that it becomes possible.
