The main reason I like sous vide, especially for the thicker meats is that I can set the machine when I leave camp and not have to worry about precisely when I come back (similar to a crock pot). The water bath keeps the set temperature and it does not matter if I am away 2 hours or 12 hours - the meat will be perfectly cooked and ready to sear when I return. I like 2-inch plus thick steaks, and cooking them by this method makes them perfectly uniform throughout the thickness, which is nearly impossible to do via grill alone. When I return to the rig, all I need is a minute or two per side and all is good, no matter how thick the cut.
As to storage, it only occupies as much space as a stick blender. I don't pack a crock pot, else I'd have purchased the Dork Food controller as I've several friends that very successfully use that unit to make perfect meals using sous vide.
On an aside, the newest Anova unit is $179 and interfaces with an iPhone, with which you can control your cook