If only Armstrong had the speed to go deep.
That's why trying to compare the two would be like trying to compare an apple with an orange. I agree with everyone about Bradford, but he still represents a deep threat on the other side, whereas Armstrong is a possession receiver. If you want to compare him to someone, compare him with Gaffney.
The difference between AJ and Bradford, is that with AJ, Carr doesn't have to be accurate with his deep throws . . . he'll find a way to get it. With Bradford, Carr has to throw it perfectly, drop it in his lap. All he's got to do is hit Bradford deep just once in game, and it'll make much easier on AJ.