Depends. If it doesn't cost me additional vacation time from work, probably go with a legacy. If it's a matter of fewer vaca hours, probably go with LCC.
Also depends on price. I just swapped a WN award flight with a DL first class flight b/c the difference between what I paid vs. the implied cost with WN miles was about $40. DL F vs. the greyhound of the sky for $40 was a no brainer.