CJB
Two of the films you mention are the two main films I use all the time, Ilford Delta 100 and HP5.
I can only tell you as I find and why It is I use them.
I use Delta 100 developed in Prescysol EF for my landscape work. The reason being is that it gives me very sharp prints up to the size I print, 11 x 8 ish.(it will go beyond) The grain is very fine and almost non-existant, and smooth in the sky areas.
whowever.. if I use it for a portrait it is too sharp. Good for the chiselled moody look of a male, showing every line and hair on the face...but...any women wouldd slap you for using it...
So... I go for HP5 in Prescysol for portraits as it gives smoother flesh tones (IMHO) and softer edges. I do not use it for landscape as I find it a bit too grainy for my liking, espescially in the out of focus areas and the skys. Beautiful for Baby shots as their skin looks like porcelain.
I must add...These findings are for these films in my chosen developer. Different developers will change a films character.
I hope this helps a little.
Stoo..............(not spell checked, sorry)