Whenever I play Roller Coaster Tycoon, I have a habit of designing a roller coaster, testing it, and deciding it is too short. Usually the ride gets good marks, but I feel that I want more track. I go back and add track to it, and more often then not, it ruins the ride (for some reason I can't help but keep doing this to my rides.) It also lowers the capacity of the ride.
Okay, I know that RCT isn't real life, but I think that the same can be said in real life. Longer is not necessarily better. Look at all of the complaints about MS and how boring the second half is. Most people seem to think that if they took out the second half of the ride it would be better. I don't know that I agree, but the fact remains that longer is not always necessarily better.
MF has been praised for maintaining its high speed thoughout the ride. Making it longer would take away from that aspect of the ride. It might be better, then again it might not be. The fact remains, MF was designed the way that it was due to space, price, and what the park wanted in its ride. I hear that MF is a great ride as it is, so I'll take people's word for it until I ride myself.
I'm sorry for making this post so long, but once I started on this reponse, I couldn't stop.
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...and enjoy the rest of your day at Cedar Point, The Am-aaaa-zement park!