I've used the AG 4D 100, Bio 200 Lite, and now use the AG 4D 200 Tour. They all feel very solid and comfortable compared to other brands.
The Bio Tour is heavier with a lower SW than the 4D Tour so I can't comment directly on the Bio version. But the 4D version is very nice. You need to prepare early and swing smooth. Arming the frame won't work. To develop sufficient RHS you really need to use a full shoulder turn given the frame's relatively high SW. Do those things and you're rewarded with plush, very controllable power. Of all the frames I've owned this is my favorite on serve given its combination of power, accuracy, and spin potential. Volleys are another strong point as the frame is very stable.
Graphene Prestige S mod: 337g, 8 HL, SW 330
VS Touch Black/Focus Hex 1.23 @ 58/54