I just posted a question in the C6 general forum and thought I would post up another question just to see what wide band others are using? I'm looking at a NGK AFX Wideband.

That's the one we use in the shop. It has excellent accuracy for an inexpensive wideband.
Also, it was designed by ECM (http://www.ecm-co.com/) which makes OEM/Professional AFR instrumentation systems.
Oh, and marketed by NGK which makes the sensors.