I imagine the Sweeping Strikes DC will likely use full rogue levels, Dexterity and add trip bonuses if we compared it like other DCs. The problem with Sweeping Strikes is, I believe, that it is compared to Balance and it should be using a Reflex saving throw or be totally modified to be compared against a straight Strength check like PnP. Balance should be affecting the chance to get up, not the initial saving throw. We haven't finished the review for the trip abilities so I can't answer questions yet. We are working as fast as we can!
Sev~