The super 7 is really a different ski to the regular s7. The super has metal (as well as a longer TR), where the regular s7 does not.
Both use the combination of rocker, camber, and reverse sidecut type shaped tip/tails. Main difference between the two is the tip to tail taper. The JJ as about 3mm, where the S7 has almost 20mm. Basically this means that the S7 shape is much more directional, and aimed more at skiing forwards. The mount is also further back than the JJ, so again, more geared to skiing forwards. The JJ's shape is designed better for skiing both forwards and switch. It's a bit stiffer, so is probably better in chopped up snow. Both are great skis, but if you don't ski switch, I think the S7 would probably suit you better.
In my mind they are two slightly different ways of creating a ski for a similar purpose. Regardless, they are both super slashy, fun skis, and you would be happy on either.
Another one to check out is the ON3P Billy Goat like SB suggested. it's a closer to the S7 than the JJ, and the construction/build quality is better than both. I'm kind of biased towards ON3P though as I have a pair and have another ordered for next winter. The Bamboo/Carbon layup is amazing. Awesome company to deal with too. Scott & Rowen will look after you.