Doepfer

i've only fairly recently begun to build up a Doepfer modular system,
and needless to say it has proven addictive (it's actually all Keith
Emerson's fault, ultimately. when i was 10 years old i saw him on TV
with his Moog Modular, and  I knew ever since that i had to have
something like this).
anyway, i'm still relatively inexperienced, i.e. still working at
discovering all the possibilities (certainly not a total novice
anymore though). nevertheless, at the back of my mind there's always
the 'what module to add next' question. 
this brings me to the A154/155 sequencer. currently i'm using the
A-191 in combination with Cubase to create sequences and control
modulation. i'm trying to find out whether it makes sense to actually
add a hardware sequencer -  what can one do with it that can't be done
with the above combination?

TIA & regards,

heinz