Adding weight?!

So Shadow has been loaned a spraydeck and a wooden kayak seat. I've been going with the theory that by changing anything on the boat will add weight and adding weight is never a good thing. But, I may be proven wrong, the seat ensures that I am sitting in the center of the boat, but is slippy. The spreaydeck is a beast to put on, but keeps my feet dry. Time will tell, how these new additions fair.