Before I get into the details of each, I think it's important to remember one thing about sequels - they rarely work. Here's why. When we think of a show that we like, we remember things how they used to be. However, since a sequel is usually many years after a series, everything, by necessity, has changed. So the original dynamic that we loved no longer exists and everything is off slightly. That's why we'll never like a sequel as much as the original - everything has changed, and though it may have changed for the better, it's no longer the same.
The KAOS organisation has developed a bomb that can dissolve all clothing. Maxwell Smart is brought in to foil this evil plot. This was quite a disappointment. I was never the biggest fan of "Get Smart" but I certainly enjoyed what I saw as a kid. This felt like a cheap made-for-TV movie. The only real saving grace was Don Adams, who was wonderful as Agent 86, the role he was born to play. They clearly took a few jokes from this movie, or maybe the show too.