Haven't got Tiger (not out in Japan yet). I can't imagine it feeling better, smoother or more accurate than this, but I imagine it has a lot more options and of course courses.
No problems with drift. When trying out frisbee at first we were messing around (removing the sensor bar) etc and we managed to get it to think it was pointing left when it was pointing forward (or maybe the other way round, can't remember), but pressing the B button to select a frisbee weight instantly brought it back in line (as is common in most of the games).
BTW, removing the sensor bar you can still go for ages without it going out of sync, it seems. Drift isn't going to be an issue with WSR.
Whenever you have to use the menu it calibrates, whenever you pick up a ball/frisbee with B, or when you're pointing down you press B, it syncs up. It's really done all the time so it's not an issue.
Impressions continue...
Bowling:
-So much faster now that you don't really need to worry about position.
-You can do anything you like, shot wise, and it works.
-Essentially, the z-axis rotation that you end your throw on determines the amount of spin, which makes it really easy to judge.
For example:
Start your throw with the wii remote in the usual position (so that if you follow straight through, it ends up flat, forward, facing the TV with the buttons up-side).
Finish your throw with the remote 90' rotated counter-clockwise (buttons facing left), and your ball will spin across about half of the lane.
Finish your throw with the remote 180' rotated counter-clockwise (buttons facing down) your ball will spin right across the lane.
Then, it's just down to variations within those (it's totally analogue) and of course power (for when the spin starts to take effect) and start position (for where you spin from).
It's pretty amazing how much faster the game goes with this in play, and also you can really carry through some awesome pick-ups for pins left standing, without doing any lining up of your character or changing angle.