In the US BAH are neck deep in Fed Defence work, have been forever. If you are referring to UK then not sure.The roles will have a different weighting - expect a more forensic, detailed approach at BAH (in effect more engineering than consulting) - which if you want to progress in defence work will be invaluable. Longer term, your fiercest competition in the defence sector, in cyber security, wont be colleagues from Accenture or BAH - it will be ex forces techies used to working on subs and warships. So the closer you start to the nuts and bolts the better. BAH would probably put you there sooner - and sec cleared. That said, you couldn't go wrong with either - both have very strong brands, but my shilling is on BAH (just).