Both of these are the best spell recursion creatures imho, with spells decks generally preferring the 0/4 wall body rather than the 1-mana discount for Archaeomancer and a wimpy 1/2. Both are solid, though if you're running Snapcaster Mage, I'd stay you probably just want the Wall, as you really don't want too many of those effects.
But isn't Salvager of Secrets just better than the wall? I mean, even in a control deck I would image that trading with some X/2 is better value than just keeping a 3/X in check for a few turns. And in tempo decks for example, having that relevant body on the board to attack after you got your Removal spell back is also nice, right?