I tossed up long and hard re: the Zephyr vs the EB - was the EB too bulky, would the zephyr have enough space - there are loads of these threads on the forum.
For everyday use - sans laptop - the EB is much roomier than I really need - plenty of space and on the border of being perhaps a little too bulky.
I travelled with it for the first time a month ago with laptop - and the EB is perfect. I had a braincell with 14" laptop, snake charmer with mouse and cables and a couple of novels and bits and pieces in the main pocket. It was perfect, and I suspect the Zephyr may have been a bit on the small side for me.