I use him, circumstantially, for precision based Earth battle tanking, because he can usefully be used to balance health regeneration with other damage elements elsewhere, in that he restores health while using the weapon buff , I use him for nothing else. I would not use him for pure tanking, the better passive options are Superman and Lex Luthor and typically you won't be carrying a weapon buff in pure tank role in favor of other more useful shields, so his use in pure tanking would be unjustifiable and impractical.
As an Earth tank, that 4.9% defense you get when in a group, roughly amounts to the bonus defense given by the earth tank buff (65% of dominance converted to defense) if you spec 340 points in dominance. In other words, an Earth tank (in a group) with no ally and 340 points in dominance will have about the same defense as an Earth tank with the ally and 0 points in dominance. Do with this information what you will. I haven't properly tested how much that ~5% percent extra defense actually affects your damage intake. On a related note, does anyone know if being in a group instance by yourself still triggers the buffed 15% defense bonus? Deathmike out.
