Some accents are perceived to be 'worse' than others - Birmingham, London, Liverpool accents are considered to be 'less educated' than say Yorkshire; a West Country (Devon, Somerset, Cornwall) accent is thought of as agricultural, and their people as slow and methodical, and the best English is said to be spoken in Inverness in the North of Scotland!  It is certainly a very pure speech, even if not exactly 'Oxford'!

So perhaps one could say that one might be able to tell a person's social standing from the way they speak (although some people learn to speak in an affected way to try to convince others that they are better educated than they are!), it doesn't always work, as there are so many factors involved.  It's much easier to detect a regional way of speaking, although this a not always reliable, either.  For instance, although I was born in Devon, and can put on a Devonshire drawl, I say 'castle' and 'grass' rather than 'proper' English 'carstle' and 'grarss', because my mother used the North country short 'a', because she was born in Lancashire.  People don't bother so much about accents as they used to - they are all part of the wonderful diversity of the English Language, and there has for some time now been a trend away from standardisation.   How about the conversation shouted between a mother and her child in the Midlands:  Mother: 'Bist tha comin or bist tha baint?'  Child:  Bist tha goin to hit me, cos if tha bist, I baint!'  And I remember that I couldn't understand my Grandmother when she was talking to her neighbours!

So, take English as it comes, and don't try to read too much into social backgound!  One of its joys is that you can speak it badly, but you will still be able to make yourself understood.  Intonation and stress is much more important than pronounciation.