I have found ellips useful for building up my gluts and quads, and maintaining an excellent level of cardiovascular fitness, while watching an intelligent TV documentary and engaging my brain at the same time. I choose not to walk in the dark after work during the winter for obvious reasons. If it's sunny at the weekend and I have the option to take a walk, that's a different matter entirely - for sure I embrace that whenever I am lucky enough to have the opportunity.
F 5 ft 3. HW: 196 lbs. Primal SW (May 2011): 182 lbs (42% BF)... W June '12: 160 lbs (29% BF) (UK size 12, US size 8). GW: ~24% BF - have ditched the scales til I fit into a pair of UK size 10 bootcut jeans. Currently aligning towards 'The Perfect Health Diet' having swapped some fat for potatoes.