Series Review: Mistborn by Brandon Sanderson

I first read the first Mistborn trilogy years ago at a time when I had forgotten how much I love fantasy. This series definitely re-awakened that love in me and got me reading fantasy again and for that, I will always love it. After this series, Sanderson wrote another trilogy in the same world with the same magic system, but hundreds of years after the events of the first trilogy. He's apparently now working on a third trilogy in the same world with the same system. While these books are all considered part of the Mistborn series, I'm breaking them up by trilogy - and today, we're starting with the first trilogy. Here is the description from the first book (taken from Goodreads):

In a world where ash falls from the sky, and mist dominates the night, an evil cloaks the land and stifles all life. The future of the empire rests on the shoulders of a troublemaker and his young apprentice. Together, can they fill the world with color once more?

In Brandon Sanderson's intriguing tale of love, loss, despair and hope, a new kind of magic enters the stage — Allomancy, a magic of the metals.


PROS

• UNIQUE MAGIC SYSTEM - This magic system blew my mind. Some people are born with the ability to ingest certain kinds of metals (just little flakes of them - not eating a block of titanium for breakfast) to use in various ways (i.e. pushing or pulling metals, influencing feelings, etc). A small group of these folks are able to ingest all the metals to use all the powers - and these people are called mistborns. It's an incredibly specific magic system that is a lot to understand when told outside the story, but Sanderson does an excellent job of making it easy to understand within the tale.
• MEMORABLE CHARACTERS - Our main character, Vin, is tragic and tough and such an excellent heroine, especially as she develops and gets more in touch with her feelings. Kelsier, her mentor, is heroic and a bit reckless while still being a genius and revolutionary. Their band of misfits changes as the trilogy progresses, but each character is unique with memorable (and realistic) characteristics that make them grow dearer and dearer to the readers as time goes on. In addition, each character has an arc and has chances to grow and change throughout the books - for better or for worse. It's wonderfully refreshing to have characters as static as much as these characters are.
• PLOT TWISTS - Sanderson is well-known for his twists and that was one of the impressive parts of this series to me. The first book all deals with trying to overthrow a despot. The remaining books confront the consequences of the characters' actions. Perhaps all is not as it seems, especially as you compare the beginning of the first book to the end of the third. The plot twists blow your mind - and completely make sense within the story.
• TAKE PLACE IN A LARGER UNIVERSE - Sanderson is a unique writer in that he connects all his writings. Most of his work is connected by being in the same universe - or the Cosmere. As you read more of his work, there are small connections you can make. And it's rewarding to see characters or magic systems you loved being mentioned in other books.

CONS

• SO MANY DETAILS - Sanderson's fan base is dedicated and really really REALLY in-depth. If you don't believe me, spend five minutes on 17th Shard's forum (the official fansite) - these people tear apart every word in each book to try piecing together what will happen in the future and all the details of each magic system. And this is the kind of series where you can do that. Even after reading most of Sanderson's work, I'm still a bit fuzzy on a lot of the details of how things ended up and why certain events were significant. While this confusion never detracted from the main plotline, it certainly made it difficult to completely understand the magic system or what exactly is going on for each character. Now, for some readers, this would be a pro, not a con. But for me, I don't want to have to read a paragraph 20 times to understand some small detail that hints at another book's future. I want to enjoy the series and the story and the people. 
• BITTERSWEET - Each book ends on a twist, but some of those twists make you really really sad. Like the end of this series - some things work out perfectly and some people you really like die and it's so sad, but somehow not as sad as it could be and you're really glad they succeeded in some things, but it isn't as happy as you want it to be and there are too many emotions to handle.

Have you read this series? What are your thoughts on it? What pros and cons would you add? What makes you want to read an epic fantasy series?