It's actually a lot of fun. You had better be prepared though if you're going to try and catch everything you want to see. I will not try. I tried the first time I went several years ago. I had a good time, but my feet, legs, and lower back took a major beating. As Surge mentioned, you learn to compromise early. Whether that's conflicting set times or conserving your body to make it all the way through. Especially with the venues being rather a good distance away from each other this year, it's all about the planning. Definitely not unique to MDF though. Any 3+ day fest with 12 hour days is going to get tough as it goes along. Pacing and planning.