The Peaked Deck's single beam gives a sharp triangular shape with steep sides. It's a classic look that sheds water very well with less parts and is therefore a little lighter and slightly quicker to build.
The Flattened Front Deck has two extra beams that creates a less steep angle and flatter top. This design provides a lower profile for the same amount of internal space as a peaked deck. This shape provides a bit more room for you toes.