I use it fairly often when making chicken or roasts. I’m very happy with the results and it does speed up the cooking.
I have not had as much luck with baking cakes and cookies. I haven’t mastered it I guess. It’s supposed to be really good if you are baking on multiple racks, which I almost never am doing, so I haven’t tested it.
Usually, you have to lower the temperature 15–25 degrees, depending on the original temperature recommended for a regular bake, but the difficult thing I have come across is some ovens seem to automatically do the subtraction, while others you need to adjust it. I would suggest checking the information pamphlet the oven comes with.
A side note: Electric ovens are typically more even at baking than gas, so the convection might really improve the baking evenness for you, but I don’t know why it would change how much the oven temperature drops if you open the door? Gas is better for some cooking though, supposedly the humidity is different, and for broiling is fantastic in my opinion.