IMHO if you get your processing right, you won't be able to tell one from the other even at big (8-10x) enlargements since they're both just beginning to show grain at that point. The granularity when printed is pretty similar despite the differing emulsion technologies.
The main difference is that Delta is about 1.5 stops faster for a given contrast and has a straighter curve.
I wouldn't go making any such generalisations about one film suiting a particular subject or anything, they're both just films and they record whatever you shine on them. The lighting of your subject has far greater impact than any film choice.