In the summer of 2012 we built our first cob project… a cob pizza oven on a cob/glass bottle base. The details of its construction can be found here. From digging the foundation to cutting the doors in the fire cob dome took 7 days of working on it part time. We then let it dry slowly over a couple of weeks so from start to first pizza night was roughly 3 weeks. The insulation cob went on in a day. The plaster took 2 days, one day for each of the two coats.
Since it was first built, we have used it extensively to host pizza nights and bake fresh breads. The food that comes off of it has a wholesome, delicious, smoky warm flare to it that is unlike any other oven we have ever used. The oven itself has held up well and so far has not needed any repairs (although we plan to repair the cob of the oven door in the spring since it is showing some signs of wear). It is also currently protected from erosive rain onslaught by a hung tarp which looks awful. It is on our to-do list to make a cone cap for it as we did for the tandoor.