The built-in disposal is basically irrelevant. The ones without have some kind of filter that rarely needs to be cleaned out. With enzyme detergents these days, you shouldn't pre-rinse dishes for any dishwasher - but you still need to scrape even if you DW has a disposal!

Heated elements are more controversial. The ones without heating elements are more energy efficient but require that you use a rinse aid or your dishes won't come out dry. Personally I like having heated dry - I want my dishes clean and dry all the time. Even so you can still end up with small amount of water in cup and mug indentations.

We have a top of the line Bosch which we bought a couple of years ago -- not sure of model #. We are very pleased with it,especially how quiet it is. Just a couple of extra db numbers can make a noticeable difference in the noise level.

The Bosch works very well. We just take a paper towel or used napkin to wipe excess food off the plates before stacking them in the DW. We don't use a rinsing agent. Whether you need one may depend on the hardness of your water.

The Bosch is the best DW we've ever had.

I have a friend who has an Asko in one home and has owned a Bosch. He currently owns a GE Profile and is very unhappy with it. It just doesn't clean like either of the others.

I personally prefer the Asko to Bosch because of the very large capacity in racks, and because it dries better (especially plastics) Some people have had service issues, I understand, but ours has been flawless in almost three years. We have six kids, and it gets used 2 or three times a day.

With either a Bosch or an Asko, you don't rinse, you scrape the big chunks off and load the dishwasher. They'll clean fine. Both are quiet and will work well. i do recommend a little rinse agent, but use a small amount first and dial up only if your water hardness demands.

It's not what you asked, but I pretty much have my heart set on a miele. I'm sick of fighting with my dw.

Supposedly the European models get the dishes dry without the heater bar, and as a bonus, they don't melt your measuring cups or catch your wooden spoons on fire (not that you'd put wooden spoons in the dw) when they fall through to the bottom.

I've also learned that installation can make a difference in dw quietness. I've recently learned that our dw has no cabinet walls on the sides of it, allowing noise to flow out all over the place. My next dw will probably (hopefully) be installed before the complete remodel, and we'll build walls around the dw cave before installing a new unit. (While learning this we learned that the countertop on our sink wall is supported by almost nothing on the front, and very little on the back- no! don't lean on that!)

More variables, that's what you were looking for, right?

We had a bosch for a 6-8 weeks and I returned it for a Kitchenaid. The bosch came damaged with a dent in the front door. The dishwasher was back ordered and after a month it was still back ordered. They didn't know when it would come in. In that time, we had a chance to use it. It is super quiet, I would say silent. The drawers are smaller and I realized that I liked having my dishes dry when the cycle is done. Bosch, recommends that you let it sit overnight to allow the condensation process to work. For the most part, if you waited 4 hours the dishes would come out dry. Having 3 back orders, we decided on the kitchen aid, we love it. It has bigger drawers, which is important for us (family of 5) It is not silent, but it is very quiet. Do I miss the Bosch, no , not for our needs.

I saw a unit sold at sears a while back that had a row of 'lawn sprinkler' sort of sprayers in the back: looked like the first genuine advance in how DWs are designed I've seen for a long time.

But does anyone know if they actually work, who makes them, and if any of the models in question have them?

Just remember Bosch has no dry cycle

we had a bosch in the old house (the entry level that allows use of a cabinet panel) and loved it, so we're getting the same one for the new kitchen.

the lack of heated drying isn't a factor. it dries far better than many dishwashers that have the electric heating element.

we considered dishwashers with the disposal feature for about a minute and then agreed that putting dishes that dirty into the dishwasher seemed gross.

we looked at miele, with it's nice upper-tier silverware tray, but couldn't justify spending $300 extra just for that. as for the many 'features' all the various dishwashers offer, we found that we basically use 'normal' cycle and almost never anything else, so didn't really consider features much.

YMMV