The Beethoven is surely an unqualified success. With the Concertgebouw playing the piece for all it's worth, and with the conductor allowing things to flow with natural momentum this is a performance to live with. Everyone will have their favourite Fifth - actually mine's Kleiber's DG version with the VPO - but this one is a joy to hear.
The Sibelius is, I think, also very successful as a performance of Romantic music, but not so much a great performance of Sibelius. A strange thing to say? Well possibly, but if you are looking for a version of this piece that lets it sit properly within the glorious cannon of 7 Symphonies, then this is not the place to turn. What Szell delivers is indeed a gloriously Romantic conception, complete with sweeping strings, singing winds and searing brass. What is almost totally missing is a sense mystery and atmosphere. The age of the recording doesn't help because there is a restriction to the dynamic range, but it's also in the conductor's conception. For sure the orchestra delivers what it is asked to deliver, and Szell clearly delivers the performance that HE wants, but it isn't in the final analysis very Nordic in feel. I will admit that the big, almost granite-like brass is along the right lines, but the sheer voluptuousness of the strings and Gallic-sounding winds are not all that appropriate for Sibelius. Try comparing this to Vanska's Lahti recording and you will hear how Finns would expect it to sound. Segerstam in Helsinki even manages to get the larger string body of the Helsink Philharmonic sound lean and authentic, as does Berglund.
But at the end of the day I will still recommend this as a great listening experience. Just please don't make it your ownly version of the Sibelius. If you really must have only one version then I would suggest choosing from any of Vanska (at the moment only the Lahti version for me - I am not yet sold on the Minnesota version), Davis on LSO Live, Blomstedt in San Francisco, Alexander Gibson (Scottish National Orchestra on Chandos) or either Jansons version (I marginally prefer the Oslo version on EMI, though the Concertgebouw recording is also rather good). Of course there are many, many other versions that I would recommend, but for 'one version only', any of these would do just fine for me!