If the max. sensitivity is not enough, you can raise the mouse sensitivity in the game, that will help. Per default the Touch controllers are in keyboard/mouse mode, so the rotation speed is linked to the game’s mouse sensitivity.
If a game has gamepad support, you can also make the Touch controllers act as Xbox gamepad directly. For that you have to change the controller mode in the vorpX ingame menu.
I put the mouse sensitivity to max in the HL2 options and it was so effective that I had to drop the VorpX mouse sensitivity to 10%! I’ll tweak the two and find settings that work for me, but I’ve got more than enough range now to find perfection.