Generally speaking, both Bosch and KitchenAid dishwashers get good reviews overall. Each brand has particular features that could better suit potential purchasers with specific types of needs. Factors that could influence your preference for one of these dishwashers vs. the other include design, quiet operation, performance features, energy efficiency and overall ranking by professional reviewers (or lack of inclusion therein).
Bosch offers two dishwasher lines: Integra and Evolution. The Integra line includes concealed controls and a design that blends well with general kitchen decor. The Evolution has generally similar features but also a child-lock latch safety feature. KitchenAid, on the other hand, in addition to the traditional undercounter dishwasher design, offers dishwasher types specially designed for use in compact living spaces or for those with minimal dishwasher usage needs: drawer dishwasher and in-sink dishwasher.
Product review site ConsumerSearch reported on the Bosch SHX98M09UC model dishwasher as the quietest dishwasher available in the United States. However, Dishwasher Review's site reports on the KitchenAid dishwasher technology as "takes sound reduction to the next level" and describes it as "the quietest operation." This suggests that in choosing between Bosch and KitchenAid dishwashers with quiet as a factor, you will need to visit a retailer and hear both dishwashers in operation.
Bosch offers such performance features as delayed start setting, a special glass-care cycle and special drying techniques that result in no steam when one opens the dishwasher. There is, however, a drawback to the drying techniques: Some consumers reported dissatisfaction with the lack of a heated drying cycle and have found the dishes do not dry as rapidly as they would like. KitchenAid dishwashers have a special Pro Scrub cleaning system and also incorporate a special rack system. Further, KitchenAid has four wash arms whereas most dishwashers have only two, a feature that also enhances overall performance.
Performance - Hard Food Disposer
For carefree, rinse-free dishwasher operation, the KitchenAid dishwasher line has an advantage over Bosch, as of November 2009. Bosch dishwashers have no hard-food disposer facility, a point noted by ConsumerSearch in a review generally rating Bosch dishwashers quite favorably. KitchenAid dishwashers, however, do incorporate hard-food disposers, which may prove the deciding factor for some purchasers.
If you have a concern with energy efficiency, then the Bosch dishwasher line may have an advantage over KitchenAid. Bosch dishwashers have an Energy Star rating, whereas professional review sites make no mention of energy efficiency ratings for KitchenAid dishwashers. However, the trade-off is that this level of energy efficiency for Bosch dishwashers is partially associated with the no-heated-dry cycle, which some consumers have found unsatisfactory.
One last consideration in a comparison between Bosch and KitchenAid dishwashers is professional review response. ConsumerSearch, which evaluates numerous existing reviews by both professionals and by consumers to compile a comparative ranking of the top three or so models of the product under review, includes Bosch in its dishwasher ranking report. However, KitchenAid dishwashers made no appearance on the ConsumerSearch dishwasher report. This translates to ConsumerSearch having, in overall comparisons, placed KitchenAid dishwashers in at least fourth place in rankings whereas one Bosch model made the ConsumerSearch report of top-ranked dishwashers overall.