Personally I don't think the ATX has been out long enough to provide a fair comparison between the two. I've never used either machine so I can't suggest which one to choose, but as good as the ATX looks on paper, sometimes it's better to stick with proven technology at least until more independent testing is carried out.
Ultimately the decision is up to you and may come down to previous experience and trust in a particular brand, budget, availability, current wind speed and precipitation etc etc.
Good luck with your decision.