I’m sharing my thoughts because I own a W968 Gold Grand Slam, a Gold Grand Slam Commercial, and a Q968, and I just received a W968S Six Gold yesterday.
I’ve played with quite a few premium Butterfly blades—ALC, ZLC, SZLC, SALC—and for the past year and a half, I’ve been playing with the two Grand Slam models, primarily the W968. These high-end blades aren't "bombs"; they are fast, but the control is excellent. Comparing the two, the W968 is superior in every respect: control—whether at the table during the short game or from mid-distance—spin generation on topspins and serves, and blocking. It has a medium-high throw angle (like a Viscaria) and a soft feel that offers great feedback in the hand... all with very, very slight flex. In contrast, the Commercial version is slightly faster, has a firm feel (without being rigid or hard), offers less control, is less suited for spin-oriented play (though it still excels at it), has a slightly lower throw, and features a handle that is a tad thicker in the flared (concave) version...
The Q968 is a completely different beast: harder, with a low throw angle and even more speed—yet still controllable—but it demands a lot of physical effort! It doesn't suit my game, so it’s staying in my collection... I might try playing with it again later using soft rubbers (40–44 degrees max).
At first, I played with boosted H3 BS Neo National (39-degree) rubbers, but I realized they were too physically demanding for me. I switched to the V15 Sticky, and then the V15 Sticky Soft, which suits me much better. That said, out of all the rubbers I’ve tried since 1997 (over 100 of them—I'm a total gear junkie!), the H3 generates the most spin! As for the price, I’ve always managed to buy them for under €400—brand new in the case of the W968s, the commercial Gold Grand Slam, and the Q968. I even got the W968 Gold Grand Slam used for €200! They are all authentic... So, you have to do a bit of searching to find the right one for you, and then play with it to experience the feel and the enjoyment...