How about "none of the above?"
I purchased a CED Millennium 2 last week, and have run rubber bands (in my kitchen no less), .177 pellets, .40S&W, .45ACP and .44mag through it without a single hitch. It's brains are remote from the sensors and the cables are long enough to set the display right on the bench. It has a built in standard USB interface (no custom cable required) and comes with the software necessary to download your shot strings to a computer.
$189 at Graf's with free shipping.
"You need only reflect that one of the best ways to get yourself a reputation as a dangerous citizen these days is to go about repeating the very phrases which our founding fathers used in the struggle for independence."
- Charles Austin Beard