David (Literature on here) will probably jump in with better info / experience, but he touches on them at the start of this review: http://blistergearreview.com/gear-reviews/dynafit-radical-ft-2-0
I've got probably 25-35 days on Speed Turns this year. They definitely have their limitations, and are NOT a hucking binding at all, but for going uphill fast they're hard to beat.
've done some stupid stuff on mine, gotten air more times than I should have, and jumped off a few things (usually with the toes locked) and haven't had too much trouble. Biggest thing is making sure it's soft snow, making sure that you land in a balanced way, and, if it's questionable I'll usually hot-tub the crap out of it.
Super fun binding if you use it for what it's designed to do though, although it's way light and overkill for just side country stuff.
Hope that helps!