I just looked at both machines on the Sizzix website. It looks like the starter kit for the Big Shot includes the multipurpose platform now.
Last winter when I was thinking about getting one of these, the Big Shot did not include the MPP, but the Big Kick did. That's what sold me on the Big Kick (along with the great deal I got on it from Costco.com... not sure if it's still available there, though). I've been very pleased with the Big Kick's performance, and should you opt for it over the Big Shot, I don't think you'll be disappointed.