The Bosch appears to be half priced because of the dent and scratch condition. As long as they give your cousin the same warranty as a cosmetically perfect new machine, I would go with the Bosch. Even the entry level Integra (hidden controls) and Evolution (front controls) do a great job cleaning dishes. The 600 series is far from entry level and is close to TOL. Would go for about $1000 if new out of the box.
The Ascenta budget line, with its partially plastic tub, may be an exception, I am not aware of anyone posting here about Ascenta with real life experiences.
One other factor to consider: you might have your cousin check with the local utility to see if rebates are offered. If one model qualifies for a $50 and another does not, based on energy efficiency, that may factor into the final decision. I can't speak for where you live, but here in SoCal the utility websites have a section for available rebates and usually you can download a list of the model numbers that qualify.
I posted the link to San Diego Gas & Electric's dishwasher rebates site. Perhaps your cousin's local utility does the same. Sometimes the merchants are aware of rebates, but at a scratch and dent center people are more focused on larger savings stemming from the cosmetic condition of the machine than whether they will get an extra $50 from the power company. If you download the list at this link, you will see that dozens of Bosch models qualify, while only four or five KitchenAid units qualify.
Bosch dishwashers do NOT have a soft food disposer, so you do have to scrape the dishes, but there is no need to rinse them. I do know some people who put dishes into a KA without scraping and they come clean due to the soft food disposer, but in my opinion that's why we have garbage disposals. I make microwave oatmeal for breakfast most mornings and I just throw the bowls--with dried on oatmeal--right into the Bosch without rinsing, they come out nice and clean. But I scrape uneaten food off the plate before placing them in the machine.
