Garageband '09 Lessons -- Any Good?

[powz]

For those who've tried Garageband '09's piano and/or guitar lessons, are they any good? Can you describe them a bit and give your impressions as to whether you can actually learn an instrument (and to what level) with the lessons? This is the main reason why I want to buy iLife '09, so please let me know what you think!

 

[chrisli75]

They teach you too fast...

I had to repeat the lesson a few times to learn it.