Just as an FYI, the Whirlpool brand encompasses Maytag, KitchenAid, Amana, Estate, Jenn-Air and others. Build quality is roughly equivalent.
Some of these appliances are US made, others are not, so if that's important, do your homework. And like their competition, most microwave designs on the market are outsourced to off-shore companies, even by halo brands. You'll find lots of LG, GE, Hotpoint and WP microwave parts that interchange.
Gone are the days when one brand is 'better' than another. Even within the same product line.