I just want to throw in a tip on a backpack that carries 2 pieces of Elektron gear and cables headphones and also a laptop.
Mono EFX 365 DJ. http://monocreators.com/the-365/
Perfectly fits my octatrack and Analog 4 with their plastic top covers(not a keys tho of course) and a small towel or piece of cloth in between to not break the plastic of the covers if it gets bumpy.
Cheers!