Student or Learner
What do you think his spoken english? Poor, Average, Good or Excellent (same as native speaker level)
YouTube - Globe Forum 2008 - Part 1. David Tang on scepticism in the business community on climate issues.
Native. British accent. Perfectly spoken.
Native speaker- although he started learning it at 13, he's completely natural.
According to the Wikipedia entry, he went to school in Britain, which accounts for his accent and his fluency. Over 40s may not get that good a pronunciation, but there's nothing to stop them reaching a high level.
Marlene Dietrich's English was still very poor when she was nearly 30. Take a look:
YouTube - The Complete 1971 Copenhagen Interview Part One
YouTube - The Complete 1971 Copenhagen Interview Part Two
She's 60 in the videos. Her foreign accent is still recognizable but I wouldn't call it strong. And her English is more than very good in my opinion.