How much bigger than a 257 is the 258?
I have a 256 as well and have been using the 257 for travel as a personal item that I carry along with a small roller suitcase.
I usually carry my DSLR, chargers, batteries, sunglasses and a spare lens and a small lightweight jacket and some snacks. It's a tight fit with my DSLR and lens especially when I bring the laptop.
I'm wondering if there is a better option. 258? or other suggestions?