i have the similar lock - the magnum 3039 with cable, and i also have the Kryptonite New York Fahgettaboutit minilock. if i know i am just running between home and work office, i will often not bring any lock since my Mu SL sits under my desk in the office.
if i am expecting to run about town but within view range i will bring just the magnum lock and cable since that is quite light. on a few occasions at some events where i had to leave my bike unattended longer i also bring along the krytonite boat anchor. certainly a nasty combination, again not totally undefeatable but hopefully the time it takes for someone to beat down both, they will go for the adjacent bikes instead.