I stumbled upon the Ashkenazy/Sydney cycle when I was browsing Spotify last year and I was pleasantly surprised about how much I liked it. I also remember the M3 being good, and I liked the M1 too. He seemed to 'get' the Wunderhorn symphonies well.
I should still listen to the rest, from M5 onwards. Thanks for the reminder and review!
It was recorded and engineered on the orchestra's own label too.