I got Samba de Amigo Wii before the price drop hit for $40 and I'm still completely happy with my purchase. Honestly I think it's worth $20 for the soundtrack alone, more if you never got the Dreamcast version and have the chance to play with casual gamer-type friends.
Regarding the controls, I don't think they're nearly as bad as everybody claims once you learn to work with them. Keeping these tips in mind I can clear all the difficulty settings, and have some fun in the process.
1) The most important thing to remember is it's not nearly as much about the location of the controllers as it is their orientation. Controllers pointed upwards for the vertical position, straight forward for the middle, downwards for the lower position.
2) I find it much easier to control via the wiimote and nunchuk than with two wiimotes, even with the cable occasionally becoming a nuisance. Either the weight or the rumble of using two wiimotes throws me off.
3) The way you hold the controllers in your hands makes a big difference. It's not entirely consistent so you have to work with it, but generally holding the controllers sideways facing inwards works better than the usual facing up position, and holding both controllers faced upside down works even better. This will throw off some of the pose positions but it's worth the sacrifice.
4) Getting into the music and movement - aside from making the game more fun - often seems to help with the controls. It can be hard on the more frantic levels but slightly exaggerated movements for the upper and especially lower positions helps a lot. It sometimes helps to kind of jut the controllers forward for the upper and middle positions and to both shake and slightly push them down for the lower one.
5) It's not as much a control tip, but on the levels where the targets come fast and furious and alternate between using a single controller and both, it can be a lot easier if you move both controllers to the same tempo even when only one target is up. The game doesn't seem to penalize you much for hitting targets that aren't there (only for missing ones that are), and even when the timing for the left and right beats are slightly staggered, you're better off hitting them both at the same time even with the timing a bit off than missing them altogether.
I'd encourage those of you who got fed up with the controls to give the game another go with these tips in mind, especially #3, and see how it goes.
Oh and looking at this post I realize there's all sorts of sexual innuendo to be found but I assure you it's purely coincidental.