For all intents of what you are wanting to get out of the guage, yes they are pretty much the same information. However I'd look at the EGT as being more towards the narrow band A/F meter than the wideband as it basically is only telling you if the cylinder temps are on the rise where the A/F can tell you more of why they are on the rise. This is the reason I chose this route over an EGT.
Rick
