What's the difference between Boxes and Downloaders?

[Walker]

Is it just the ability to shift on the fly? Do the programmers like Superchips etc. only run the program you have entered at the time (having to stop and re-download another program if you want a change)?



What are the advantages/disadvantages of each (code reading/resets, transmission shift changes , etc. )How bout' power? Are all the programs between the two similar?



Just trying to get a grasp on the differences for a near future build-up.



Thanks