The old K2 Wayback with a 88mm waist was a great success. It was a bit heavy (a bit more then 3 kgs per pair). K2 has now made the K2 Wayback 88 quite a bit lighter (2560g per pair at 174 cm). The narrower (82mm) and wider (96mm) K2 touring skis are now also called Wayback. PS: I owned two pairs of the old Wayback and found them just great and seasy to ski.
The new Wayback 88 also gets good reviews and can be recommended (even if there are lighter skis with the same width). I could not find an Englisch review online, sorry.
Test in Bergzeit Magazin (in German): Great overall ski, good edge grip etc.
Test in Outdoor Magazin (in German): “Wunderwaffe”, versatile etcThe wider (and clearly heavier) K2 Wayback 96 also seems a good choice for more freetouring oriented skiers:
Test in Outdoor Gear Lab (here): “Every tester liked the Wayback, but no one loved it.” “Great value.”
Summary: Overall, it seems that other skis such as the Fischer Hannibal 94 or the Salomon MTN 88 or the Blizzard Zero G 85 seem to have a better performance/weight ratio than the K2 Waybacks. But the K2 Wayback 88 (or the Wayback 96) can still be recommended. While there are not the lightest ski, K2 skis are versatile and easy to ski. The price of K2 skis is (in Europe) lower than most other brands. Great value!