[Cob] cob vs adobe

[Maggie Henry]

Does anyone have any experience using both? Recommend one over the other? I
have read EVERYTHING I could get my hands on dealing with cob oven
construction. I found the Sunset Adobe Oven project directions and because I
want a Quebec-style was hook immediately because of not needing to build the
form. (The alder branch form from the Bread Ovens of Quebec looked
daunting!)
 I didn't really read the materials list on the Sunset oven and it was news
to me when someone posted "don't use portland cement"  Cement? That's not in
Kiko's book. So I actually read the entire project article. Sent me off
researching adobe.  My new question is which is better? Longer lasting? Can
I just cob over the form? Has anyone actually built one of these. I am
determined to get this done this summer!
Thanks in Advance for all your help!

Maggie