The pros are that you can cook at 2 separate temperatures, so food requiring to diff temps it is ideal. It also doesn’t cross-contaminate different types of food. The downside is cost as they are more expensive and size as you end up with a medium and a small oven. I can tell you from sales experience the customers who have purchased double ovens from me are very glad they did and would do so again. In a double GE Profile and Cafe seem to make the best ones.

So I think you mean “convection” a convection microwave is telling you that it has a second heating source, usually a radiant element. This means the microwave will also bake like an oven and brown foods, vs. a traditional microwave that just has 1 heating source. A magnetron that disperses microwaves to cook food but isn’t the best for making things crispy. Almost all convection units feature a stainless steel interior, so it’s a quick way to tell if it has the extra cooking modes.

So for me in the Northeast, I see the approximate cost if the gas is accessible on the basement below around $550-$800, plus you will need a 110-volt line for the gas stove so consider that as well.

Here is a great blog post where I address that.

https://justaskal.info/a-list-advice-when-is-the-best-time-of-year-to-buy-appliances/