Does the microwave really bake and roast?

Yes. The microwave has a convection mode, so it circulates hot air like a small oven for baking and roasting. Expect it to handle smaller batches, not full-family meals.

What cutout size does it need?

It is a 30-inch unit, so it is designed for a standard 30-inch wall oven cabinet opening. Confirm the exact cutout and depth in the installation guide before ordering.

Can I use the microwave and oven at the same time?

They are separate cavities with separate controls, so both can run together. Check the electrical requirements, since running both draws more power than either alone.

How does it compare with a separate wall oven and microwave?

It saves the cabinet space a stacked pair needs and gives you convection in the microwave. A separate pair gives you independent replacement and a wider choice of brands.

Is it worth it over a cheaper countertop microwave?

Only if you are already fitting a 30-inch wall oven. The built-in look and convection mode are the draw; a countertop unit costs less and takes counter space.

What comes in the box?

The combo unit itself, plus the racks and accessories for the oven and microwave cavities. Mounting hardware and trim are included for the built-in install.