x2 for Duratracs.... Love mine.
But I've never seen or used the SA's.... Go look at 'em at a store... one look was all it took for me to know they were what I wanted.....
They see a lot of mud, and have never gotten us stuck, and they are great on road as well... There's probably still a $100 rebate on them through www.treadlightly.org
too, not sure when it ends tho'.