Parked finish, more polish and honing on internals, metal trigger group, no mods requried to add a tube extension, heavier springs/lifter, and sling swivel studs. All this can be changed, if you look at Wilson Combat/Scattergun Tech, or AIP, Vang Comp, most use the express for their builds to keep costs down, and change only what they think is necessary, but if you can buy a used police magnum or wingmaster (only difference being parked vs blued) for less than an express, why not?