Oh yeah! I haven't been on S7s yet but everybody I've seen on them at my mountain has loved them. A averaged size guy on 188s was saying they carve on hard ice groomers, skied out groomers, and tight powdery or cruddy trees and all types of variable and powder, open or tight spaces alike. Everybody I saw demoing them loved them too. That would be a very good choice. They're pretty popular on TGR for all types of conditions and charging Note that the 188s are actually going to be a little shorter than that, and with that sharpp tip and tail at the end, and taper and rocker, they will turn short when needed. I'm not sure how big you are, but there's a 195 too.
If you aren't skiing switch(and who the hell skis 99.9% of powder areas switch ever, or variable conditons switch?) then skis made to go forward are going to be better than skis made to go both ways(so..pow jib skis). The charging ability of a ski like an S7 compared to JJs will be far from close. I was with a guy at Whistler last season on a pair of 188s and he said you can go switch easily on groomers and in powder you can but they don't turn a ton when riding switch. Really I haven't talked to anybody who doesn't like them, and a bunch of the patrollers at my mountain prefer them.
Good idea...I completely forgot about them. You could also look at 190 Bibby Pros, but they don't have that nice big tip and tail taper.