The Consumer Affairs website has 78 ratings for Kitchenaid microwave ovens as of 2015, and they average one and a half stars out of five, indicating that other brands perform better. Out of 21 reviews for the Kitchenaid KHMC1857WSS microwave/hood combination, 4 earned two stars and 13 earned just one.
One consumer on the Consumer Affairs website had repeated repair needs with her Kitchenaid microwave oven just after she had owned it for a year. The microwave/convection unit cost her over $1700, but it refused to respond to replacement of just about all the major parts. The Amazon review does contain complaints about performance but also has testimonials praising its durability and performance.