I own both and would give the nod to SS. It's just a pure classic masterpiece that's getting harder to find. Pretty much everyone loves it whether they are a pinhead or a never played before. It is easy to get to the stiff-o-meter, but very challenging to beat the mode. I have had the game for about 6 years now and it's not going anywhere, but I did have a period where it collected dust for a while when my collection was smaller. As someone else said, it's a game you can walk away from for a while and it will feel new and exciting again when you come back to it. At this point with the code, Met seems much more repetitive with no ultimate objective.
Brian
Ontario, CA
