I think if you didn't have an oven available it would be nice since you can brown foods in it. We have one at our cabin in the mountains, just thought it was overkill since we have an oven and three outdoor grills to choose from (plus they are closer to the beer and wine fridge).
I have a convection feature on my oven at home and use it, especially cooking pizza inside. I crank it up to about 500/525 and it does a really nice job, especially if you have the proper pan for the crust (small holes in bottom).
Check prices as they were quite a bit more expensive than a normal microwave when we got ours, but that was quite a few years ago.