the die cast line is the same size as the small ships included as part of the series alpha set.
also, the same molds that were used for the die cast line, were also used for the x-ray line.
one of the amazing details given by galoob to their star wars line was that by making so many different sized ships, (die cast, action fleet, micro machines, etc.) a proper sized scale ship can be found from one of the lines that matches up in scale to a ship in another line.
example:
the micro machines snowspeeder compares properly in size to the action fleet at-at
the die-cast x-wing compares properly in size to the action fleet millenium falcon
better yet, the micro machines rebel blockade runner (tantive VII) compares well toe the kenner collection series star destroyer.
there are a lot more favorable size match ups through the lines.
go get em, and have fun!