Dear fellow Singapore-based FTer,
I had a similar profile --- based in SIN, life-time star alliance gold (via UA MM, UA 1k for 18 years), oneworld emerald for a few years (AA), SQ gold for a few years. I started looking at AS last year. Did the AS platinum challenge, banked 70k+ AS miles last year with AS partners (SQ, AA, JL, etc.), did segment run for 6 AS metal flights on the west coast, and finally landed as AS MVP gold. No regret so far, except that I could have done 6 more AS segments to get MVP 75k.
Will continue with the same strategy this year. So far had one JL roundtirp from SIN to west coast, with 2 segments on AS.
AS miles have much better value for J redemptions on JL and CX!