I have never submitted to either, but I would recommend this; call each mag and ask about submission policies, what they pay for articles etc. Will they take a submission that is simultaneously being submitted to another source?
IMO, the two magazines have a different tone... maybe that can help you, read some of each and ask yourself where your article would be the better "fit". Maybe ask some trusted friends to do the same thing and go with the one that your article fits better.