This is one of those "to each their own" topics. We've had gas ovens in every (five) motorhome and the last two have been special orders. Personally, I can't imagine having to depend on only a convection-microwave which we've had in the last two motorhomes. Yes, you must have a separate oven thermometer for gas ovens. It's essential because the temperature dials are the pits and we've had two different brands of gas ovens. I finally bought airbake pans and cookie sheets and they did the trick. For casseroles I use the airbake pan and for things like rolls I use the airbake cookie sheet. For the uninitated, airbake sheets are cookie sheets of double thickness with an air layer in between. I liked the one I bought for the motorhome so well that I got another one for the house. As to microwave-convection (or even straight convecton) ovens, I'm not that thrilled with them. They're okay for some things but - to my way of thinking - not everything. In both the motorhome and at the house I use the regular ovens more than the convection ovens. They say that convection ovens bake at lower temperatures for equal or less time, but that's not been my experience. Also, it took me months to get the ovens at home calibrated properly. I remember the wonderful things my Grandma baked in her old 1920s gas oven and they just don't make 'em like they used to! She never burned anything...
By the way, there are airbake pans with holes in the bottom and without holes. If you get the kinds with holes, it's important to make sure they drain well after washing, or you'll end up with rust and/or wet shelves. I bought a couple at the kitchen booth in Quartzsite. It's the one that's right across the street from Tyson Wells. I spend more there than I do in "regular" stores!
ArdraF