I've listened to the recording a few times. The playing is note perfect but also engaging, the ensemble always precise and synchronized. Based on this recording, I can conclude that for the past six years Chung has built the Seoul Philharmonic Orchestra into a world class band (these are not just my own words!). It is built from bottom to top, with solid bass instruments, dark strings, prominent woodwinds, and golden brass. The strings in particular have flexibility in their tone and phrasing, a rarity in typical Asian orchestras. The trumpet is impressively rock solid and never fails to register even in the thickest passages. Ditto the horns and trombones. We know all of these are the essential elements in performing Mahler, don't we? Top top it all, Chung has a few surprising but genuine touches in his sleeves, such as the dreamy, slow introduction in I., the sudden speedup in the coda of I. and II., the expansive middle passage in III., the slow and long second theme in IV. Speaking of the tempo shifts, Chung applies with such care and intuition that none of them sound forced or artificial. Needless to say, they all work to great effects to enhance the drive, energy, and romance in the piece. Overall, Chung's interpretation reminds me of Eschenbach/BSO concert at Tanglewood that I attended in the 90s.
The only downside is that being recorded at the sonically notorious Art House Center, Seoul, Korea, the recording lacks somewhat in the bass. But otherwise, the DG recording team headed by the renowned producer Michael Fine captured the concert with clarity, a good balance, ambiance, and a startling presence.
So, all things considered, this is a Mahler First to treasure.
I suspect this is the version I will turn to most for now.