I've had this CD for a long time and am starting to listen to them again on a daily basis. This is one of my favourites as the music is so relaxing and non-repetitive. It's absolutely amazing for when I am working - headphones in - and I feel really relaxed. You'll have to make sure you don't drift off, though - it's also wonderful for sleeping and relaxing at home.
I read a review of another CD of someone who gave it as a present and the person hated it because of the 'voices'. That's the whole point of this CD. In real life, outside or in the office or at home, there are always people talking around you, and your brain picks up elements of conversation that interest you. These could be bad things because of the way you feel. You must have heard someone say something even when you weren't listening attentively - and then you start listening to them - certain buzz words. This is the same, but it's in a musical format, and within music, and structured specifically to improve your happiness and confidence. A lot of the reason why we aren't confident is because we keep thinking negatively about ourselves. This 'forces' you to think positively, and it's a nice change.
Does it work? I personally think that people telling me constantly that "It's OK to like people" "It's OK to be liked" and "It's OK to be peaceful" etc. etc. will mould me into that person. Which is perfect. But you're meant to listen to it subliminally - hence the beautiful music. It's sometimes hard not to focus just on the words, but mostly it'll just be the music that you hear especially if you're being productive. In this subliminal respect, I am pretty certain that it works - I've only bad examples like Hitler's swastika and music propaganda of dictatorships etc. - but this totally reverses the aims yet retains the method. It's also really up to date with wonderful music - so for these reasons, I heartily recommend it. For a taster, this one - Confidence - is one of the best in my opinion.