We used a free standing commercial gas convection oven at the restaurant, which was later replaced with a similar sized electric one. Functionally, they seemed fairly much the same. The gas unit, I think, came up to temp a bit faster from stone cold; it was somewhat noisier, which I doubt had to do with the fuel; the electric oven was more flexible for position and venting, which is why the owners changed. If you bake a lot, you will probably break even, money-wise, in the end. Baking times are significantly reduced, as are hot and cold spots, minimizing the cool down you get by opening the oven for frequent rotation.