Got around to trying this game today. First tip, turn off the 'voices' option in the audio settings... the announcers are really annoying and repeat themselves multiple times in a short time.
First thing you notice is driving the boat around is kinda awkward, a/b is forward/backwards, and twist/tilt is steering. What really makes this decision odd (could had used thumb stick for steering) is that you're required to keep the nunchuck plugged in at all times. And playing through the game all controls could had been easily mapped to the wiimote alone. Nunchuck can be used to reel in the fish, by shaking it (simulating turning the reel)... but that can also be done with use of the B button.
There is one big thing I do like about the game compared to SEGA BASS Fishing. Once the fish is on the hook it is less about managing tension (worry of the line breaking)... but it is more about keeping the fish on the right side of the tension to keep from getting off the hook. You do this with a simple mechanic of only reeling when the fish is centred in screen, or pull the wiimote to the opposite side to try and bring the fish back to centre. I think this is well thought out.
Overall the game is slower moving then SEGA BASS Fishing's fun, up-tempo, arcade style. But for those who want the more simulation approach, this might be the best the Wii has on offer. I wish the game didn't tease you in the intro, it uses a FMV from the Xbox 360/PS3 version to get you excited. Then you get dumped in to the 'average' Wii quality graphics, though they really aren't that bad (no worse then SEGA Bass Fishing). Overall for me maybe a 6.5/10. It's not going to be enjoyed by everyone (where SEGA BASS can be enjoyed even by non-anglers), but this version of Rapala for Wii seams like a decent game for the audience it's trying to appeal to.