I'm carrying the DE 35 B this week and love it as it fits everything u need including extra sweater and files for work. I have speedy 30 in mono and DA and like both sizes for different reasons/situations. You can't go wrong with either size.
the 35. easier to carry and not as big as you think it is. I had a 30 ebene. it was too small for everything when I needed to carry a lot. and too big when I only carried a few things. the 35 is perfect. I don't know why. but I don't seem to lose things in it. get a bright colored base or use bright colored SLGs inside.