I'm wanting to order a custom laptop messenger from timbuk2 here, but I don't know what size will fit a current unibody 17 inch MBP. According to the dimensions listed by apple here, the medium would bag would fit it fine. On timbuk2's site the large says it fits most 17 inch laptops, but the true width is too big. However, the true width on the medium bag would seem to fit. Does anybody use the medium timbuk2 messenger bag for their 17 inch MBP? I've searched and have found a lot of people using the medium bag for their 15 inch MBP and they say it fits "perfect". Some people mention that they use the large bag for their 15 inch also. The site's specifications would seem to fit perfect with a medium bag, so i'm not really sure. I would prefer the medium bag, but I don't want to waste my money since you can't return custom bags. Any ideas?