Barshai and Shostakovich were long associates, and Barshai's farmiliarity shows right through this set, which pulls the best out of a mid-ranking German regional orchestra. The real strengths of this set are its remarkable consistency of conducting, playing and sound quality over such a long cycle - none of it absolutely mindblowing, but all of it very good. The discs were originally released as single CDs over a 6 year period which probably helped keep conductor and orchestra fresh.
Its main rivals are the Naxos CSPO set which, sorry, doesn't begin to compare either in terms of performance or recording quality, and the Haitinck which costs considerably more.
It is thin on background material, but then again so much Shostakovich background remains disputed that most synopses fall down by presenting only one side of the argument anyway.
This boxed set has become my 'core' set for symphonies by my favourite composer - and it costs barely more than a full price version of a single long symphony. Just don't give yourself indigestion if you're new to Shostakovich - 5, 7, 10 and this wonderful interpretation of 15 are the ones to start with. The 'clockwork' fading out at the end of the last symphony, with Shostakovich aware that he way dying, is absolutely haunting.