I have an Italian oven called Pizza Express made to the same concept as the Pizza Bella, but from G3 Ferrari: http://www.g3Ferrari.com/en/
I find that the major problems are:
1) Lack of height in the oven between stone and heating element, and
2) the diameter of the heating element is too small.
If a pizza is larger than the circular heating element in the lid or above about 8", it easily touch the heating element and crust or toppings burn to carbon in seconds.
Also, the outer rim of the pizza does not bake enough, when the pizza is made larger than the heating element.
However, if the pie is small enough, it makes a good result when the tweaking of the thermostat is right. The instruction tells you only to bake the pizza during the time the heating is on, so it means in my experience, keep the thermostat around mark 1½ to 2, and crank it up to 2½ to 3, 30 sec. before the pizza is loaded onto the stone.
I will measure the distance between the heating element and the base when home later today, and it would be interesting to have some measures of "The Bella".
The major advantage of the oven is that it is quite quick to heat, and will take the first pie after 10-15 minutes heating up.