Mstislav Rostropovich knows the power of slowing the tempo. He has consistently used it to convey the false triumph, the horror, of the finale of Shostakovich's 5th Symphony -- his 1983 DG recording with the National Symphony Orchestra is my choice for the best recording of all time (see my review). To take another (in)famous example, Celibidache has been roundly criticized for his exaggeratedly slow tempos in Bruckner, but this produces, in the live recording of Bruckner's 8th with Celibidache leading the Munich Philharmonic, a unique and incredibly powerful performance. Clearly there is nothing inherently wrong with a slower tempo, as Rostropovich showed with his earlier LSO Live recording of Shostakovich's 11th Symphony (see my review).
Unfortunately, it doesn't always work. And despite the beautiful and precise performance by the LSO and another superb LSO Live recording of the November 2004 concert at the Barbican, this 8th drags and fails to capture the drama, energy, intensity, fear, panic and horror of war that makes it the Guernica of 20th century music and one of Shostakovich's most powerful symphonies. Listening to this recording, you wouldn't know that it is one of the best and most powerful compositions of the 20th century!
The time for this performance is 68'45". By contrast, Rostropovich's 1991 recording with his National Symphony Orchestra on Teldec ran just over 61' (see my review), slightly faster than Haitink's powerful 62' recording on Decca (see my review). Solti's 1989 recording with the Chicago Symphony Orchestra on Decca, now out-of-print, my choice for the best 8th, also runs 62'.
The most serious problem with this Rostropovich/LSO performance comes with the second and third movements, the Allegretto and the Allegro non troppo. These are the movements that convey the utter horror of war, if they are played properly. Solti nails them, and Haitink takes them just slightly too insanely fast, which still works. But -- my apologies to Rostropovich, who knew Shostakovich well and claims unique insight into the composer's intentions -- he does not create the taut forward drive and momentum to bring this mighty symphony to life. The fast movements were the fatal flaw in his otherwise excellent Teldec recording, and now with the LSO, the outcome is even worse. There are beatiful passages to be found within, but the overall story is lost, and with it the meaning.