Night Train's man. I've skied S7's (which I didn't like all that much to be honest), SFB before last year/this year's redesign, ARG's, Czar's, and JJ's.
I can't say anything about the Opus. It looks bad-ass and fun.
If you want to feel like you're becoming a better all around skier(sharing opinions with people I ride with) I'd get:
Moment Night Train's
ON3P Billy Goat's
You can pick up something like a JJ or SFB super easy and they're fun, but what I and everyone I ride with notices- is that the skis you have to take little time to adjust to become the most fun skis and you really feel yourself getting better in the deep stuff. You also become reluctant to try anything else.
I have the JJ's and Night Trains now and am probably going to get rid of the JJ's as my "it hasn't snowed very much this week" skis. The Night Trains are phenomenal in pow. Whether it's up to your ankles or waist, you'll feel like you're a fucking pro.
Which brings me to a potentially high-jacking question. Late-January to mid-Febuary is probably when I'm going to get new daily drivers. I use my Night Trains about 95% of the time, but they will become more of a dedicated powder ski when I get new daily drivers. JJ's are going (anyone want to buy?) and my question is how would the ON3P Jeffrey be for an all-around ski? Does anyone own it?
I watched the recent edit in the park and pow with them and it's just amazing. http://vimeo.com/51412939