When I first saw Jayce I thought I was sure I wasn't gonna like him.
But when he got released his awesome skin just made me wanna get him.
After playing a couple bot games I felt a connection with this new champion.
I found out that he is really cool to play.
That's why I will try to teach you guys what I know.

Pros
Great mobillity
Can adept to team
A good addition to the team and a great help in ganks
Fun to play
Not item dependant
The abillity to switch to long ranged

Cons
Can be difficult to master
If you don't know how to handle ur mana U will be useless
Easy suicide when making small mistakes

I choose for the flat AD Marks and Quints to make farming in early game easier.
For some extra survivabillty I get Flat Armor seals and Magic Resist per level glyphs.
This is for making sure you will not get bursted down by AD or AP carries in early game.