A comment on the controls for people having issues:
From what I can tell, there's a difference between sword orientation calibration, and "cursor mode" calibration. Even if what is considered center cursor alignment drifts, my sword doesn't. Also, don't point the wiimote at the sensor bar to reset it. That is not what you're aiming at.
The wiimote is not being used in IR pointer mode in this game - the tip of it isn't supposed to be intrinsically locked to 1:1 to the cursor on the TV. The wiimote is an air mouse. When you hit down on the d-pad, it snaps the camera cursor straight, center, and level, and assumes that you're now holding the wiimote level in your hand at whatever position your arm is comfortably resting in for playing. This isn't about holding your arm up and sighting down the barrel at the cursor on the screen.
Using the down button reset is more like recentering a mouse on a pad when you've moved it too far. It's almost like the solution some proposed for first person shooters on the Wii.
If you're playing at an angle that the wiimote does have sight of the sensor bar, it seems to ping that every so often to keep itself centered without user input. But that appears to be a backup system. Mostly, this interface is designed to be used, again, like a gyroscope air mouse on the PC.
As for swinging the sword at angles.. big motions aren't required. It's more about lining up the position and angle of the sword at a normal movement speed, since that part is 1:1 with the wiimote, then snapping your wrist along the desired path. That triggers an actual slash animation with a hit box. It's similar to Red Steel II but doesn't require motions as big as Red Steel II. This is designed so you can play it sitting down, with hands on your lap or knees.
And doing a spin slash doesn't require a big motion either. A short snap of both wrists in either direction will trigger it. You don't even have to wind up by first moving left, then snapping right, or vis versa.
I don't want to discount folks who are struggling with the controls. All I can say is, I am not having trouble with the swordplay. I'm using a standard Wiimote with the external attachement, so I've got no possible calibration advantage of a Wiimote+ with the extra gyro closer to the original gyro inside the case.
ﾉ*:･ﾟ✧