Schumann's symphonies have so often been berated for their poor orchestration that there is a particular case for seeing, or hearing, if a performance on instruments that come at any rate a little closer to his own expectations makes any difference. The answer here is ambiguous. For one thing, there is little in the symphonies that cannot be clarified on a modern orchestra by tactful conducting and responsive playing; and rescoring the works loses something of their essential nature. For another, matters are not automatically solved by use of an 'authentic' orchestra. I have not seen the specification for the instruments used here, but there are some oddities: I doubt if Schumann, with his particular feeling for the instrument, would have enjoyed everything that happens with the horns and their relationship with the rest of the orchestra.
For yet another thing, there is the question of recording. Whatever Derek Solomons wanted near the start of the First Symphony just before the piu vivace, it cannot have been the partial obscuring of the flute quintuplet figure and the total obscuring of its clarinet answer (in track 1, at 1'47'' and 1'56'' respectively). I doubt, too, if the recording's heavy favouring of the cello pizzicato in the slow movement could be regarded as in any way authentic to Schumann's wishes (track 2, from 2'21''); and the cello also predominates over the oboe it should exactly match (not an easy one) in the Romanze of the Fourth Symphony.
There is further the matter of pitch and tempo. The pitch favoured is not quite a semitone below modern pitch. Tempos sometimes sound unconventional. Tempo is not, of course, the same as speed. The finale of the First Symphony is marked at minim=100: this is almost exactly what is adopted here, but it sounds slow because there is some lack of the qualification Schumann gave the tempo marking, Allegro animato e grazioso. There are no absolutes as far as pace is concerned: ear-witnesses agree that Beethoven conducted his symphonies more slowly than later became the fashion with most nineteenth-century conductors, such as Mendelssohn, a notable exception being Liszt. So it is not the letter of authenticity which counts but the spirit, and partly through the recording this is not always present in these performances. They should certainly be heard, and pondered.'