I reckon it all depends on what kind of learner you are. You either learn better by visual stimulation (Tabs & sheet music), audio stimulation (working it out by ear, like me) or Kinaethetic stimualtion (hands on, work it out by playin it or sequencing it as you feel).
I work best by listening to it.
I try to get a MIDI file of the song, if it's available, and bring it into Anvil Studio (Freeware!). Then i am able to isolate different parts and listen to them, seeing how they work together. This program is also good if you like to look at the piano roll or sheet notation to work it out.
My thoughts.