We went up to Stuttgart Bahnhof to switch Elder Holm for Elder Sorensen, the office sent me a plan that included a train that we couldn't take, so we had to stay in Stuttgart for about two or three hours. It was alright though, I ate about 20 chicken nuggets by myself, and I got to see Elder Petty, another elder in my MTC group.
About my new companion, Elder Sorensen: He's pretty cool. He loves going finding a lot more than Elder Holm did, and he likes ice cream a lot more too, which are both good things! He also likes to clean.
About the question: "Why is the Book of Mormon important?" There's the missionary's answer about why the Book of Mormon is important, it's because if you know that the BOM is true, then you know that Joseph Smith was a prophet, and then you know that he really did (or that God did through him) restore the church. That's what's important, or at least the answer we hear every time out here.
UPDATE: Personally for me, the Book of Mormon is the most important thing that has happened in the last 2000 years, for obvious reasons. It contains the words of Christ, words we never had heard before, it teaches doctrines that we had totally lost from the church. It is The Book to read when you need comfort in your life. The missionary answer is very important to me as well, The Book of Mormon allows us to become unshakable in our testimonies, or at least to get on that path, and pray to God, and you can know it is true.