I still use V4 for all the assets I've accumulated throughout the years and the ease with which I can work with her.   I don't find it hard to un-vickify her or give her expressions.   I spin dials, I move stuff around, I play with scaling and that's part of the fun!  The addons like Perfect Victoria, Real arms, and many other morph resources make it easy for me to pose and morph her.   I don't doubt Vicki 7 will be much better but as a hobbyist for the past 16 years I figure I don't need to spend more money when I still haven't used over 50% of what I've bought for her not to mention what I haven't even installed yet.