As it is coming up to Halloween, there is an abundance of cheap pumpkins in the shops now. I quite like to eat pumpkin rather than carve them. Are the large round orange pumpkins good to eat are are they just grown (with lots of nasty chemicals/fertilizer) to only be used as carved lanterns? From the outside, the shell seems very hard so maybe they will be quite tough. I would more than likely roast the flesh and use it for soup.
From the two other related questions highlighted by @Jefromi, one referenced this article that states:
"All pumpkins may be eaten, but there is a big difference among varieties. Decorative pumpkins, which American children and patient parents carve just before Halloween, are grown with color, structural strength, a flat bottom, and a sturdy stem as their main attributes. The flesh tends to be bland, watery, and fibrous. No one cares because they're going to be carved and smashed in the street (or disposed of properly)."
So from that I would assume that the decorative pumpkins are not very good to eat.