A couple more things with respect to others' questions...
I got mine for Christmas and started cooking our own family recipes with it in January... when it was cold outside... and I had no sun in my backyard and was cooking with it on my front porch. :) We haven't had max summer sun even. I can pre-heat mine in 30 minutes or less. Correct angling for sun exposure will maximize the temp but so far I haven't gotten mine over 400 degrees. Every time you open it, you lose about 20 degrees. It is very forgiving, convection baking style and kind of like a crockpot. I've baked bread at 350 for 55 minutes; I've purposefully baked bread at 200 degrees for almost 3 hours - both to perfection.
Water temperature does not have to come to a full boil to have killed the bad stuff and be safe for use. The WAPI gives you a visual tool for knowing when it is, without a doubt, safe for consumption.
I have not used any of the cookbooks for sale as of yet. I started with my own family's recipes. There are free recipes on their website at http://www.sunoven.com/solar-cooking/archives/category/daily-solar-cooking-recipe if you don't want to spend the money on the recipe books. A fellow friend said they have them at Honeyville but were more expensive than buying them through this group order. I plan on getting all three this round because I don't have as much expensive meats and dairy items as I have vegetables in my food storage, and we love Mexican food. So... I wouldn't be afraid to start with what you already know works for your family.
As far as having two, I would say yes! I definitely want two (and maybe even a third for emergencies, call me crazy!), especially, if you have a big family. It won't fit a standard 9x13 in it on the leveling tray because of the handles. You can criss-cross your pans (that it comes with) within the oven, essentially doubling your oven in and of itself. The two stackable round pots it comes with really are stackable. I'll do soup in the bottom and rolls on top. One oven could be fine. I, however, like to make dessert and usually a vegetable so I put those in the second oven that I can start later or use just so I have enough food. (A turkey takes up a whole oven; I need a second oven to really do the whole meal.) And, in an emergency situation, you could be pasteurizing water at the same time just so you have safe water to drink and wash with. If you're considering one, I would say definitely consider two.
The oven weighs about 21# and is not exactly but around 15x19x19. It folds up compact and is very sturdy. (When the reflectors are open it is bigger.)
Have a question? Just ask in the comments and I'll try to answer it for everyone.