[TenTec] Omni D (C) / Corsair II receiver info

[Ivin Flint]

I'm following some of the thread of the Omni VII discussion and I see the Corsair II thrown out there.  I hear often that it has such a great reciever.  I own a Omni C and added a  external VFO(thanks to this group)
I have read the product reviews from the ARRL and am trying to understand how the Corsair II receiver is better than the Omni D (C)  By the way I have all the filters installed in mine.

I see the features on the Corsair II has pasband filter, internal keyer, AGC but that is it that I can tell that my rig doesn't have.  Both have the same basic receiver if I remember what I read correctly.  So is the passband filter what puts it over the top?  

Just wondering how much better the receiver in a Corsair II is to the Omni C?

Thanks
Ivin W9ILF