It is worth it. I just spent the summer building one and can't get over the quality of food that is achieved ever so easily.
Two main (and free) resources I used to get practically all the information I needed were:
1. Forno Bravo website and forum
Both are full of knowledgeable and helpful people. Forno Bravo also have free plans and recipes ...
I should add that my oven is fired on weekends only and it does not take longer than 90 minutes to get to pizza making temperature, using about 1/2 - 2/3 of a wheelbarrow of dry oak or other hardwood logs (bought from the local tree surgeon, so entirely sustainable). It is not the Ovencrafters design, but a very well insulated 10/D model from Forni di Fiore.
It holds heat remarkably well, still at nearly 200C the morning after, so there is scope for some serious "serial cooking"...