I am in support of new dishwashers with filtration systems instead of chopper assemblies.
I'll get it out of the way, I will always recommend a Miele dishwasher over anything that is made. There are no ifs about it. I have yet to be disappointed by them.
https://goo.gl/photos/McdPVWrhPmCv5U7d7
That being said... Depending on what your must haves are, a new dishwasher will be around that 1k-1500 price point. I would not own a 3 or 5 series Bosch. We have had over 70 repair calls on them just in 2017. If look at a German appliance and it does NOT say Made in Germany on it, DO NOT BUY IT.
I also don't know that I would own a new Maytag with that crooked/tapered rack. We get a lot of complaints about loading things in the bottom rack. We've had to take two out because the owner's plates simply would not fit in the unit. That being said Maytag has put a powerdry option on one of their models, the 8979 that adds fan-assisted drying.
I do like the Whirlpool WDTA50 dishwasher, it blends nicely with any package that I sell, regardless of the manufacture. The Kitchenaids with the Clean Water wash system are going to have a hybrid wash system between the point voyager and whatever they call the new filter system. I say that because it has the larger wash pump but a self cleaning mesh filter system that back flushes like a swimming pool filter. KitchenAid is also adding back fan-assisted drying. The only thing is I don't like how flimsy the tubs are on the new KitchenAids. For a $1k plus dishwasher, it shouldn't feel cheap.
After rebuilding a Frigidaire dishwasher for my mom, and servicing a 7 year old Electrolux, I am really liking their designs. I will say that I probably wouldn't look at the units that have a plastic filter that has the wash arm support in part of the filter assembly. The way those units are designed, all of the debris is swept by the arms to the center of the tub and pushed directly into the wash pump intake. The new units that have the filters away from the wash arms clean much better. They also have inline heaters built into the motors or separate units in the lines. They also have a fan-assisted dry cycle. The new units with the better filters don't have exposed heat elements, so no real heated dry system, just a higher rinse temp. The Electrolux dishwashers have what seem to be some of the sturdiest racks I've ever seen in a dishwasher. IF I didn't have my Miele dishwashers, I would probably purchase an Electrolux dishwasher. I really like the way they are designed. They are heavy and feel solid. They are pretty impressive.
I am not a fan of GE dishwashers. We either have a lot of control panels go out or everyone seems to snap the latch sensor arms off their dishwashers.
LG dishwashers were a dud because we had a lot of failures early on and didn't have great support from the distributor. The distributor changed, but so did warranty processes and we ABSOLUTELY hate working with LG to get warranty claims through.
Samsung... The water wall dishwashers are growing on me.... I don't like their dishwashers that aren't water wall and its mainly because they aren't built by Samsung.
We sell a lot of Asko dishwashers in our other store, but thats because the lady that pushes them there has one and she thinks the same thing about them as I do Miele.
As far as budget goes, if it was absolutely necessary to stay under the $500 limit, I would probably say go with a whirlpool/amana. You aren't going to find something better for less.
To the longevity thing... That is all in a matter of how you take care of your appliances. If you check the filters regularly, use the hottest cycle often enough and don't OVER SOAP the machines, they should last a long time. They say cleaning power and cleanability is a trifecta, so is machine maintenance. Don't do something that will over tax the system on a regular basis, don't do something that will cause buildup of debris or detergent, and keep things hygienic (let things air out and clean parts and surfaces).
