I agree with JayL - OTR microwaves are more of a hassle than they're worth (IMHO), and they prevent you from having a decent ventilation option.
I'd rather have a countertop MW, so I don't have to reach over a hot stove, and definitely use a vent hood over the range. Even a recirculating one seems to make a big difference. It's better if you can duct it outside, but even if you can't, it will at least filter out the grease and smells. And there are hoods you can build into/under the cabinet.
My 3 cents (adjusted for inflation).