I demo'd both skis last March. First let me say that I don't usually care for women's skis, as I generally find them too forgiving and boring (yes, sorry for the the nondescript description

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However, the Attiva 5* was the best women's ski I've ever tried. Now, I must tell you that I ski a Volkl 6* when skiing the east, so obviously I prefer a stiff ski. That being said, I found the Attiva to have great edge grip, and it jumped in and out of turns without complaint. The ride is also quick and snappy.
I know lots of women love the K2 luv series, but I didn't care for it at all, with the exception of the Phat Luv which is a blast in powder. I demo'd the Burnin' Luv, and the Lotta Luv, neither of which I liked. The Burnin' Luv turned easily, but was NOT happy at high speeds, and had a mushy ride.
All in all, if your wife prefers an aggressive ride and likes to push her limits, the Volkl will be a great time. If she likes to sit back and just cruise, then the K2 will do just fine.
But judging by your description of her skiing, I think she'll prefer the former.
Have fun!