I have the canvas GP, it's very light actually. I carry my macbook pro 15" in it around for more than a year, did not change shape and still looks like new.
I have both 1 & 2 :-1. is really hard to open with one hand
2. too heavy especially with laptop inside, and one strap is always slipping off shoulder
I think Hermes Garden Party is the best bag for documents and laptop