Naxos' release of the complete Symphonies of Wolfgang Amadeus Mozart (1756-1791) is a great bargain box. The recordings of the earlier symphonies, 1-24,26,37 are by the Northern Chamber Orchestra (Manchester, England) conducted by Nicholas Ward and the later symphonies: 25, 27-41, are by the Bratislava, Slovakia orchestra Capella Istropolitana, conducted by Barry Wordsworth. Ward's recordings date from the early 1990s; Wordsworth's from the late 1980s. All are digital sound, and well recorded. The Northern Chamber Orchestra has about 25 players, but doesn't sound thin or scrawny - they use modern instruments, and Naxos does a great recording job. The Cappella Istropolitana is also well recorded, and sounds larger than the Northern Chamber orchestra: perhaps about 50 players?
Wordsworth's recordings suffer more from comparison with big name conductors of the past (and not so distant past) such as Beecham, Walter, Bohm, Szell, Klemperer, Kubelik, Krips, Kertesz, and Bernstein. Competition is fierce in Mozart Symphonies 35 and after, as almost all the great conductors have recorded them, rather like the Beethoven or Brahms Symphonies. But Wordsworth's accounts are respectable, if not always the best: 35 and 39 are very good, the others quite good. My only complaint is that in some movements Wordsworth could have repeated the exposition section, as I'm all ready to hear it again (some listeners will not agree). And some Allegro movements are a little pokey. The Capella Istropolitana's strings, I think viola section, is shaky in II of Symphony 34. But I am nit-picking: these are really quite good performances, and the price is right!
My favorite Mozart Symphonies are recordings of Bohm/Berlin Philharmonic (DG), Krips/Concertgebouw (Philips, Symphonies 21-41, with Marriner/St. Martins for 1-20), Bruno Walter/New York Philharmonic (25,28,29,35,36,38-41: Sony), and Szell/Cleveland (35,39,40,41), and I'm glad to hear Naxos' production, too.