there are two different drummachines delivered within the 7.5 package. (groove agent)
it’s drag and drop to the drumpads to load in your own drumsamples.
they are excellent machines, have multiple layering, excellent filters and so on
so you really don’t need an extra vst for it.
you can mash your drumwaves into peaces with loomash2 too if you want
look here:
http://www.steinberg.net/en/products/cubase/what_you_get.html
and if you type for example “groove agent SE4” on youtube you can see it in action
kind regards,
R.