I've only been on one (Millenium Force) so I cant compare, but all I know is MF was so incredible. I drove all the way from Minnesota to ride it, then waited 3 hours to ride it, and it was BY FAR worth it! All I can say was from start to finish, Millenium Force doesnt let up, and it was WAYYY better than any other ride I've ever been on.
NOT overrated. I reapeat NOT overrated.
To me, its underrated.