I have pretty good legs even w/o training them much so I mostly just focus on upper body.  I can put muscle on my legs pretty easily but have been there and done that and really don't care much about them being big.  But I do care about looking lean and burning calories.  Recently it hit me that If I care about being lean I should try to add muscle anywhere as easily as I can.  The metabolically active muscle will mean I am burning more calories maintaining.
If you can readily add muscle anywhere do it because it makes it easier to stay lean.