I am a big Boosh fan and I didn't know what to expect from the radio show, a lot of the Boosh TV stuff is very visual, but like Martito says below, it works and indeed sometimes better.
If you are new to the Boosh then this is a good introduction to the world of the Mighty Boosh.
If you are a fan of the Boosh but have never heard the radio show, then this is a MUST! You would not regret buying this.
They do use a lot of the ideas from the radio show in the 1st TV series, but there is enough difference to keep you interested, in fact you can play the "spot the unique material" or the "What's different in that scene"games.
Warning! Try not to listen to it it in public, as it WILL cause uncontrolled out bursts of laughter!! And this will lead others to think that you are a little peculiar!
Overall, this is a must buy for those new to the world of the Boosh and to the already converted!