Perennial...Stone Orpine 'Angelina'

I don't grow Angelina myself, but most sedums can take just about any sort of treatment.  If, at this point, the plant looks ungainly or messy because it is going to seed, go ahead and deadhead.  It can't hurt it.  You might even get a second flush of flower later in the season.  If, however, you are hoping for seedlings, of course you wouldn't cut it all back.  I don't know how well her seeds might germinate, but some sedums do provide volunteers.