Can confirm SPG rate is 1 Amex Gateway = 0.5 SPG (same rate as Ascent).
This is precisely what I did with my Explorer 110k bonus. Transferred to 55,000 SPG. I did a small test transfer first, and once that arrived in SPG account, followed up with the full amount the next day. (Both SPG transfers arrived in SPG account around 11pm Sydney time for a transfer initiated earlier that day).
Note that with the Marriott acquisition of Starwood, SGP points can be transferred instantly to Marriott rewards 3:1. So your 110k Amex points gets you 165,000 Marriott points.
I used 120,000 Amex -> 60,000 SPG -> 180,000 Marriott and redeemed these points for 5 nights in Marriott category 9 hotel in Europe (Marriott offers 5th night free on reward redemptions). The value is not as good as first class airline redemptions, but still not bad.
This is precisely what I did with my Explorer 110k bonus. Transferred to 55,000 SPG. I did a small test transfer first, and once that arrived in SPG account, followed up with the full amount the next day. (Both SPG transfers arrived in SPG account around 11pm Sydney time for a transfer initiated earlier that day).
Note that with the Marriott acquisition of Starwood, SGP points can be transferred instantly to Marriott rewards 3:1. So your 110k Amex points gets you 165,000 Marriott points.
I used 120,000 Amex -> 60,000 SPG -> 180,000 Marriott and redeemed these points for 5 nights in Marriott category 9 hotel in Europe (Marriott offers 5th night free on reward redemptions). The value is not as good as first class airline redemptions, but still not bad.