It's a good podcast, but not really just about the UK. The tips on buying quality tea are useful here in the US too, especially to newbies.
I was in the supermarket yesterday, and along with the PG Tips regular, was PG Tips Special Blend. The label indicates Ceylon and Kenyan tea, so they added some Ceylon to the lower grade Kenyan. It's still partly Kenyan , don't know the percentage, and it's still dust. But as he said, the supermarket tea buyer is not educated in teas.