I don't find Demon to be rough, but I can understand why other people do. It's those hard over the shoulder restraints.
If they replaced those trains with those found on blue Hawk and marketed it well, I think Demon would become a hit with the general public again.
It's the same thing with Viper at Magic Mountain. It's a great ride; it's just the head banging caused by those outdated over the shoulder restraints that makes the ride unboreable for many people.