Bavarian ‘Tracht’ is a complicated subject: every village has their own code for a Lederhosen and Dirndl (the girly stuff). So there is no such thing as the typical Lederhosen. They vary in length (short to long), material and ornaments. Plus what kind of shoes and socks your wear with them - and equally important what kind of suspenders go with them.
Actually wearing them is very comfy, because there is lots of room for your family jewels and the flap is much more practical then the modern zipper - especially when you are drunk.
More? Wikipedia
PS: Wearing a Lederhosen does not entitle you to Yodel, drink huge quantities of excellent Bavarian beer or stare at female Alps for any longer periods of time.
