I have listened to both, the M5 in the car, where it sounded great (the Adagietto perhaps a mite generalised alongside say Abbado II), but the real star is the Bertini Tokyo MSO M9 - that is quite superb with perhaps the finest recording I have heard on SACD, I listened in stereo only via my Stax earspeaker system.
Recorded at one live concert, the performance is incredibly powerful with amazing detail and instrumental colour brought out with astonishing clarity, for which I suspect Bertini and the engineers must both take credit.
I have to say I thought the playing was pretty stellar, I only noticed one slight momentary slip in string intonation in the finale, but that is of negligible importance compared to the many felicities and insights in this recording. The solo oboe and flute play like seraphs throughout, but the whole orchestra's performance is outstanding.
It's probably my favourite M9 now - though the Barenboim and Chailly are of course great (long time since I've listened to the latter SACD).