Looking at the last photographer's images, shot on a DSLR, they are naturally and appropriately free of any kind of compositional artifice. They work for their directness and clear interaction with the subject.
It's of course very self-indulgent to be striving for artful compositions under the circumstances, and the reason I took this on was partly to try and free my photography of contrivance.
Sent the Portra off for development today and will make a decision about the use of the Pentax when I see them.
I'd hope this thread can stir some debate about 'idealism vs. realism' regarding the use of film photography in these situations. I'm not giving up on using it yet, but trying to determine how much of it is simply about ego - as TooManyShots hinted at in his first post.