OK, I was PM'ed. Let's be clear that Forno Bravo is a commercial site for a manufacturer and seller of a particular style oven. They allow almost anything to be said on the site, but the reality is that it is biased towards pompeii ovens. Some of the posters are zealots, and some are one-oven experts, but overall the forum is a very good resource. I have only built one oven with my own hands (and it ain't round), but I do have masonry and refractory knowledge and experience.
I do see what Shuboyje points out, but please do not let that limit your use of that resource. There are just as many of that particular brand of zealotry on this forum about pizza, and it certainly does not dissuade me from using this (wonderful) resource.