Vital is a great PBX and at this pace soon become dominant on features and market share. But are lots Elastix and issabel , freepbx arround and in much cases is not conveninet replace for now. So install sonata modules there can make sense.
Anyway, a feature Vital dont have is a CallCenter module to automate outbound calls w campains, scripts and forms, and inbound callcenter too, where operator keep connected on queue all time and pbx send incoming calls. A preditive dial will be nice too. This features can be see on issabel free callcenter module.