Regarding touch games, w968 is nothing fast. It's soft with a woody feeling.
When you try to stroke or loop, that comes in the power of w968.
When using Liu Shiwen, you are more in to loop, spin, trying to get more rally, trying to be consistent, or fast near table block. Win the point when opponent make mistake.
When using w968, the loop quality is much higher and faster. Sometimes just win the point by one FH shot. Even in backhand rally, the moment you can use a full swing FH shot, it will be the winning shot.
K161 is a outter carbon blade. As Jimbob MacInbred mentioned before, it is similar structure as Viscaria but change the outter ply from koto (Viscaria) to Limba (K161). It's like a FH enhanced version of Viscaria, but sacrifice a little bit BH.
One of the common comment about Viscaria is it has very comfortable BH, because of it's Koto ply and outter ALC, it makes BH very fast and powerful. But Viscaria's forehand is a bit problem. Same, because of it's koto + outter alc, the dwell time for FH topspin is a bit shot. It is a bit hard to put enough power and spin to the ball.
K161 is trying to solve this problem. It changed the koto to limba to increase dwell time. Good for forehand, but at the same time, backhand is slowed a bit.
Anyway K161 is a outter ply blade, the feeling is different from Liu Shiwen and W968. If you more into spin game and FH game, try W968.
If you win point more with BH, you can try K161.