Maybe not such a terrible loss of value if the OP already has points in Marriott? FWIW I accumulated a modest stash of points back in the SPG days, those points were converted to Marriott with the big switchover and I still have them there. I have transferred points from SPG to AS long ago and it didn't seem to be a terrible redemption value, and in a pinch I'd do it again from Marriott to AS (although not with a huge number of points...).