I have both the rack ear set and the shuttle SM12 bag... I like portability so i use the bag... I can load into a gig with my bass on my back in gig bag, SM12 in bag over shoulder and one 1x12 cab in each hand.. One trip, and its a loud rig....
However the top and bottom have gotten a few scratches on it from use.. that never bothers me.. Plus in the rack bag it is easy if i have to fly to a date....
I could put it in the rack , but i just have not done that yet... I think the rack with the rack ears is the best protection overall... but i would get a SKB since it is lighter in weight and a very good way to keep it safe.. you dont need an Anvil style case unless you were tossing into the back of a truck or someone else was moving it for you..
But if you do get a rack the SKB will keep it light and protected and not add weight to the move.. after all that is the reason we go9t light heads anyway...