If I just want a simple comment box below my entry, should I use Django's comment framework or write my own?
Um... yes?
More seriously - whatever makes you happier. If you're in a hurry, roll your own; if you have a bit more time, by all means get to know the Django system; it'll probably be worthwhile in the longer run.
I'm split between writing my own comments model (pretty easy model, foreign key it to the entry) or using the full-out Django comment framework.
I mean, for right now, I just want a basic box for people to post a comment. That's it.