I found the Gedore ring - set spanners far preferable to the "double ended wrenches" that one gets in toolkits. This is because the ring side of the spanner is angled down, much sharper than other makes, as well as being further away from the handle (hope you can figure this out). Because of this it almost acts as a socket and can works brilliantly on the recessed bolts that you normally find on motorcycle aluminium cases.
For the larger size allen sockets, such as 8mm and 10mm, one can just cut a small piece off the allen tool and use the gedore ring side of the spanner on these pieces to undo the allen nuts. This does not work with set spanners.