All of these AC builds popping up makes me think, what would the viability of a non-AC, S&B, DR/Guard tank be? Aside from the shield feats (Shield Master, Imp SM, and Imp. Shield Bash), everything else could be devoted to DPS. It would be a mix of the two extremes. You would have all the DR (actual/physical) a AC S&B type would, but wouldn't have to worry about all the equipment (often hard to obtain). My guess is most of your saves would be about the same as well.
I only see two downsides to this. Since you would be getting hit more, your "total DR" would be lower (assuming no hit = infinite damage reduction). And you'd be vulnerable to special attacks that you wouldn't be when shield blocking.
I know there's
Tukaw, but I don't think that you could hold aggro these days. Has anyone played around with a build like this or given it some thought? I'm not too good at knowing what equipment to put where, but I think you could fit in quite a bit of guards (dragontouched armor, Shroud items, etc...).