"Does Silver on DL, a Skyteam member, offer more “value” or options than MVPG on AS?"
As a DL Silver Medallion, I rarely saw a F/C upgrade and had to pony up 50K miles every time I tried to find a domestic award seat between ATL and SEA.
Not sure, but I don't believe that Silver gives you access to the TSA priority line in ANC or SEA either.
IMHO..AS MVPG is Far Superior to DL Silver Medallion--or Gold Medallion for that matter.