Does Size Really Matter? (This is writing related! I Promise!)

Mood: comme ci comme ca
Did the title scare you a bit? Don't worry. This is a very innocent post. So that's the big question:
Does Size Really Matter?
I read somewhere that a novel should be 50k to 100k. Any less and the book looks too small. Any bigger and it looks overwhelming to the reader. Personally I like bigger books compared to small books since their plots NORMALLY are more detailed. I normally try to read books that are in between. Even though bigger books tend to have better plots, the plots tend to drag.
I was reading a book that will not be named. I've heard rave reviews so I was very excited to read this book. The first thing I noticed was the size of the book. It's 400-500 pages long. Not mega long compared to my literary companion the Harry Potter series, but it's still not a light read. I found the book very interesting, but I had difficulty diving into the book since I felt the plot was slow. Don't get me wrong. I enjoyed the book, but I just wasn't glued. Maybe it's because I read/ write paranormal books which are mainly fast plots (and kissing).
Then there are small books. I really wanted to read this book a couple months ago. I went to the book store to get it, but I was discouraged at the size. I think my pinkie was thicker. I ended up not getting the book because of this.
Now this does not mean if you're writing a less than 50k book I won't read it. I will if you ask me too (since I might not hear about it since it takes me a while to find some books.) Some books are MEANT to be hundreds of pages long. Like Harry Potter. Some books are better short and sweet and not ruined by unnecessary drama. Like Firespell. Both books are brilliant and are perfect the way they are.
So what about you? Do you write long or short books? Do you read long or short books?

XOXO