I understand Ivy Bridge is newer but I was thinking the dual channel memory may be a downgrade compared to the quad channel the SB-E has.
No. Triple channel offers virtually no performance advantage at all. For it to make a difference you need to be bandwidth bottlenecked and with a quad core processor you almost ever will be. Some clever so and so will doubtless produce a bandwidth limited scenario but these are not the norm in desktop or workstation scenarios.
Triple channel is really for 8 core Xeon based server applications, where memory bandwidth can start to be a factor.