has someone said that the net hulk broke was NOT primary adamantium somewhere.....?
as far as uru--uroc was shattered by that specialized cop team in thor when they hit him with liquid nitrogen iirc. cap's shield>prim adamantium>uru
uru becomes harder though via enchantment so thor's hammer is pretty close to primary adamantium imo.
and i agree with bran--the thing/destroyer fight was a high/low feat. ben has also given hulk hell more than once, not to mention champion. ben DOES have some awesome feats in his past of fighting people he has no right matching. i'll not rule out the idea that the fact that the host was missing played a role though.
as far as this fight-i think the destroyer would eventually take him. the beams have easily scarred mjolnir. i think the combo of beams+physical power (maestro destroyer appeared leagues beyond hulk) would end ultron, whereas i see nothing that ultron has being able to seriously affect the armor.